Skip to main content
SIIG Dual Serial PCIe Card Adapter, 16650 UART, Baud Rates up to 250Kbps, PCIe 2.0 x1 to 2X RS-232 Male 9-pin DB9, RS-232 5V or 12V Power, ASIX AX99100 Chipset, Dual-Profile Brackets (JJ-E20711-S1)
SIIG

SIIG Dual Serial PCIe Card Adapter

Bottom line: The SIIG Dual Serial PCIe Card Adapter is a specs-and-price decision rather than a crowd-consensus one in the expansion cards category, priced around $29.99 on Amazon as of 2026-10-06. Check the specification table below against one or two close alternatives — on price and spec fit, not on star ratings.

$29.99

As an Amazon Associate, SpecPicks earns from qualifying purchases. Full disclosure →

Buy on Amazon — $29.99 Compare to similar expansion cards

By , Founder & Editor-in-Chief · Listing data updated

Mike Perry — Hardware researcher since 2014. For retro PC hardware and period-correct parts, synthesises manufacturer documentation, community compatibility lists and marketplace listings rather than first-hand lab testing. Core beat: GPU performance across gaming, rendering, and local-LLM inference.

*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.

Pros & Cons

Pros

  • ✓ Backed by SIIG's warranty and support channels

Cons

  • ✗ Confirm socket / form-factor / power-rating compatibility against your build before ordering
  • ✗ Price, stock, shipping and returns are set by the retailer and may have changed since this page was last updated

Related Products

Other products in this category you may like:

SpecPicks Verdict

SpecPicks scored SIIG Dual Serial PCIe Card Adapter using a rating × review-volume × price-fit model applied to published specs and reviews across the expansion cards category. SIIG's expansion cards lineup sits within the broader category mid-tier; price and specs are the deciding factors over brand loyalty here. Judge it on the specification table and the price rather than on sentiment: check the figures that decide your use case, then put it side-by-side with two or three close alternatives in the Compare tool before clicking through.

Common buyer scenarios for expansion 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 retailer's listing before purchase. Prices and stock are set by the retailer and may have moved since this page was last updated.

Key Features

  • Adds two 9-pin RS-232 serial port to PCIe enabled desktop computers, each port supports data transfer rate up to 250Kbps, Compliant with PCI Express 2.0 Gen 1
  • Single-lane (x1) PCI Express End-point Controller with PHY integrated; Full serial modem control with hardware and software flow control; Supports 5, 6, 7, 8 and 9-bit serial formats, and Even, Odd, None, Space and Mark parity; On chip 256-byte FIFO buffers in transmit and receive path for each serial port
  • Works as either standard RS-232 port or with 5V or 12V power output for devices that require power (such as handheld scanners, table scanners, POS displays and many more). Configurable via jumpers
  • Supports PCI Bus Power Management Interface Specification Revision 1.2; Dual profile design installs into both full-size and low-profile system chassis with the included mounting brackets; Installs into any PCI Express slot of any lane width
  • Perfect solution to connect with POS system, industrial testing and control device, security system, logistic management equipment, printers, scanners, etc

Full Specifications

BrandSIIG
StyleMusic
Style NameMusic
Unit Count1.0 Count
Model NumberDHJJE20711S1
Mfr Part NumberJJ-E20711-S1
Compatible DevicesPrinters, Scanners, POS Systems, Industrial Testing and Control Devices, Security Systems, Logistic Management Equipment, Personal Computers, Laptops
Hardware InterfacePCI
Warranty Description2 Year Limited
Full listing titleSIIG Dual Serial PCIe Card Adapter, 16650 UART, Baud Rates up to 250Kbps, PCIe 2.0 x1 to 2X RS-232 Male 9-pin DB9, RS-232 5V or 12V Power, ASIX AX99100 Chipset, Dual-Profile Brackets (JJ-E20711-S1)

Ready to buy?

SIIG Dual Serial PCIe Card Adapter, 16650 UART, Baud Rates up to 250Kbps, PCIe 2.0 x1 to 2X RS-232 Male 9-pin DB9, RS-232 5V or 12V Power, ASIX AX99100 Chipset, Dual-Profile Brackets (JJ-E20711-S1) is listed on Amazon. Price, availability, shipping and returns are set by Amazon and its sellers — check the listing for current terms. SpecPicks earns a small commission on qualifying purchases — thank you for supporting independent review work.

Buy on Amazon — $29.99

*Price sourced from Amazon.com. Last updated 2026-10-06. Price and availability subject to change.

Related Expansion Cards

Keep exploring SpecPicks

Other buying guides

Browse the catalog

Editorial

More guides & deep dives from the SpecPicks archive

Browse all articles & guides →

More reviews from the SpecPicks archive

Browse all reviews →

Earliest SpecPicks reviews

Browse full archive →
SIIG Dual Serial PCIe Card Adapter, 16650 UART, Baud Rates up to 250Kbps, PCIe 2.0 x1 to 2X RS-232 Male 9-pin DB9, RS-232 5V or 12V Power, ASIX AX99100 Chipset, Dual-Profile Brackets (JJ-E20711-S1)
$29.99
View on Amazon →