3Com
3C509B EtherLink III ISA Ethernet Network Card 03-0021-004 Tested / Working
*Price sourced from Amazon.com. Last updated 2026-05-21. Price and availability subject to change.
• Model: 3C509B. Included • 3Com 3C509B ISA Ethernet Card only. Overview • Genuine 3Com EtherLink III ISA network interface card. • ISA interface expansion card. Features • Standard ISA compatible interface.
SpecPicks Verdict
SpecPicks classifies 3Com 3C509B EtherLink III ISA Ethernet Network Card 03-0021-004… as a niche pick — read recent reviews before buying in the networking cards category, based on limited Amazon review volume so far and our ranking model that weights rating × review-volume × price-fit. 3Com's positioning sits within the broader category mid-tier. Use the Compare tool to put it side-by-side with two or three close alternatives before clicking through to Amazon.
Common buyer scenarios for networking cards of this kind: matching it to an existing build, replacing a failing part, or upgrading from a previous-generation equivalent. Check the spec table below against your current setup — particularly socket / form-factor / power-rating fields — and confirm compatibility on the Amazon listing before purchase. Prices, stock, and Prime eligibility update directly from Amazon's catalog and may have moved since this page was last verified.
Pros & Cons
Pros
- ✓ Backed by 3Com's warranty and support channels
- ✓ Ships via Amazon with Prime eligibility and the standard returns policy
Cons
- ✗ Confirm socket / form-factor / power-rating compatibility against your build before ordering
- ✗ Price, stock, and Prime eligibility update from Amazon and may have changed since this page was last verified
Full Specifications
| ports | 10Base-T |
|---|---|
| speed_mbps | 10 |
Ready to buy?
3Com 3C509B EtherLink III ISA Ethernet Network Card 03-0021-004 Tested / Working is available on Amazon with Prime shipping and the full Amazon returns policy. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.
*Price sourced from Amazon.com. Last updated 2026-05-21. Price and availability subject to change.
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