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Motorola SURFboard SB6121 Cable ModemXfinity Comcast Internet

HerbertSells
(126)
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US $5.27
ApproximatelyAU $8.14
or Best Offer
Was US $6.20 What does this price mean?
The seller’s previous price is required to be the previous selling price or recommended retail price (RRP) at which it was offered and/or sold for a reasonable period of time immediately prior to the discount.
Save US $0.93 (15% off)
Condition:
Used
Sale ends in: 3d 4h
Breathe easy. Returns accepted.
Postage:
US $6.20 (approx. AU $9.58) USPS Ground Advantage®.
Located in: Williamsburg, Virginia, United States
Delivery:
Estimated between Mon, 11 Aug and Sat, 16 Aug to 94104
Delivery time is estimated using our proprietary method which is based on the buyer's proximity to the item location, the postage service selected, the seller's postage history, and other factors. Delivery times may vary, especially during peak periods.
Returns:
30-day returns. Buyer pays for return postage. If you use an eBay postage label, it will be deducted from your refund amount.
Payments:
     Diners Club

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eBay item number:405846274890
Last updated on 28 Jun, 2025 07:49:50 AESTView all revisionsView all revisions

Item specifics

Condition
Used: An item that has been used previously. The item may have some signs of cosmetic wear, but is ...
Carrier
Comcast
Model
Motorola SURFboard SB6121
UPC
0606440046624

About this product

Product Information

Those looking for a fast and reliable modem that is compatible with both Mac and Windows operating systems can look at the Motorola SURFboard SB6121 (575319-019-00) 199.68 Mbps cable modem. This model uses the SNMP and HTTP remove management protocol along with the TCP/IP network transport protocol. This unit features a 195 Mbps transfer rate and it contains four different multiplexed channels. It features a variety of line coding formats and it is compatible with 32 QAM, 16 QAM, and QPSK line coding. Other features of the modem include IPv6 support, auto-negotiation, IPv4 support, and auto-uplink for users to take advantage of.

Product Identifiers

Brand
Motorola
MPN
575319-019-00
UPC
0612572186237, 0606440046624
Model
SURFboard SB6121
eBay Product ID (ePID)
114301358

Product Key Features

Type
Cable

Additional Product Features

Data Transfer Rate
199.68Mbps
Enclosure
External
Hardware Interface
Ethernet
Transmission Line
Cable
Network Ports
F-Connector

Item description from the seller

About this seller

HerbertSells

95.7% positive Feedback•509 items sold

Joined Jan 2025
Usually responds within 24 hours
Visit storeContact

Detailed seller ratings

Average for the last 12 months
Accurate description
4.7
Reasonable postage costs
4.9
Postage speed
5.0
Communication
5.0

Seller feedback (134)

All ratings
Positive
Neutral
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  • c***u (525)- Feedback left by buyer.
    Past 6 months
    Verified purchase
    The #1 best eBay seller I've ever dealt with. The DirecTV steaming box was received quickly, and it's in like-new conditon. It even still had the plastic protection on the front. There was an issue with the box that was no fault of herbertsells, but he helped get it resolved quickly. Everything is perfect. Shipping was fast, communications were fast, and I would highly recommend this seller.
    AT&T C71KW-400 DirecTV Now Osprey Android TV OTT Box Streaming Player ONLY (#405846283495)
  • c***v (11)- Feedback left by buyer.
    Past 6 months
    Verified purchase
    This seller is honestly the best experience I’ve had on eBay! So communicative, honest, and upfront about what’s being sold and the condition. The item was as described, and came wonderfully packaged. Seriously can’t recommend this seller enough & I’ll definitely be purchasing from them again! 10/10!
    Reply from: herbertsells- Feedback replied by seller herbertsells.- Feedback replied by seller herbertsells.
    Hope this handycam brings you a ton of creative joy !
    Sony DCR-DVD 403 NTSC 3MP DVD Handycam Camcorder w/120x Zoom - Bad Battery (#405966985699)
  • 2***u (633)- Feedback left by buyer.
    Past 6 months
    Verified purchase
    The product was exactly like it was posted on the site and packaging and shipping was fast and secure. Great value for vintage piece. Communication was excellent as well. Highly recommend seller and I would definitely purchase items from seller again. 👌🏾
    Vintage Rare Nascar #24 Jeff Gordon 1998 All Over Print T-Shirt Mens Size M MINT (#405950525855)
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Product ratings and reviews

Learn more
4.6
319 product ratings
  • 251 users rated this 5 out of 5 stars
  • 39 users rated this 4 out of 5 stars
  • 5 users rated this 3 out of 5 stars
  • 9 users rated this 2 out of 5 stars
  • 15 users rated this 1 out of 5 stars

Easy to set up

Good value

Performs well

Most relevant reviews

See all 195 reviews
  • by wcshamilton
    15 Jul, 2017Top favourable review

    SB6121 PREMOD Forceware v1.4b-mod2

    This is a review of the Motorola SB6121 PREMOD w/Forceware cable modem. If you are looking for one on a stock SB6121, look elsewhere. This is a totally different beast, and NOTHING will work for you. With that out of the way: It works great for what I wanted. After reading and reading, and reading some ore, I hooked it up, changed a few parameters to let it connect, and success! Nice and fast, most options are fairly easy to understand, and it works. Make sure the "Start Mode" is set to "Online", "Tuner CFG" to MT2170, and the "PGA Type" to MT1570. If your system uses certs, READ ALOT. There are quite a few How-To's out on the Web. A negative point: It can take awhile for the modem to reboot, and then foe your router to actually get it's DHCP address/etc from the modem, and actually ...

    Verified purchase: YesCondition: Pre-ownedSold by: orangecountydeals

  • by josephfernadez1122
    09 Dec, 2015

    You get what you pay for

    I decided to choose this product rather than the faster modem, the SB6121 due to wanting to save a buck or two and because I live in a 1 bedroom apartment. The internet I receive is fast, adequate when running through the cables, obviously less so through wifi. All in all I appreciate the modem and it's usefulness. It was easy to set up and has been great thus far.

    Verified purchase: YesCondition: Pre-ownedSold by: p70yuOqQTn2@Deleted

  • by ksvitale
    07 Apr, 2016

    Older model but still supported

    I purchased this product to be used on COMCAST. The first thing the installation tech said was that it was marked as "end of life", which meant that COMCAST would stop supporting it shortly and I would have to purchase another soon. This concerned me but upon a further conversation with a COMCAST telephone-support tech, I was told that it just meant that COMCAST was no longer selling this model and would not offer tech support for it. Having said all that, the unit is DOCSIS 3.0 compatible and should work up to 170 mbps. I am only using this modem with 10 mbps service whereas COMCAST is offering up to 2 gbps. If you are only planning to use this unit up to 170 mbps service then this unit is fine. Peace and blessings.

    Verified purchase: YesCondition: Pre-ownedSold by: us_auctions4u

  • by charl.owens
    30 Oct, 2015

    Cable Modem SB6121

    Needed faster internet and cable was the only option. Cable company was charging a rental fee but gave options for me to purchase my own cable modem. Bought this used on Ebay and works great. Very happy with the purchase.

    Verified purchase: YesCondition: Pre-ownedSold by: jeremy289er

  • by bigbubba2002
    09 Nov, 2015

    Streaming demon

    Set up with Comcast was a breeze, at least as far as over the phone anyway. Works well with thru my cisco router as all 4 of my puters wired and two laptops wireless all streaming YouTube or an anime channels at same time. No choking with this bad boy. Great and I mean great buy with screaming delivery time too of only two days from purchase. Impressed I am. Easy set up, easy activation, easy money as I saves my over a "hundred dollars a year" in rental fees to Comcast.

    Verified purchase: YesCondition: Pre-ownedSold by: ssdealsprime

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