Sonnet has announced the Echo Express SEL, the latest addition to the Echo Express line of Thunderbolt 2-to-PCIe expansion systems. It enables the use of a variety of high-performance PCI Express (PCIe) cards — originally designed for use in desktop computers — with any Mac with a Thunderbolt port.

The new model is the smallest and quietest Echo chassis yet, and supports one low-profile PCIe card, according to the folks at Sonnet. The Echo Express SEL incorporates ultra-fast Thunderbolt 2 technology, which delivers twice the bandwidth of Thunderbolt and provides sufficient throughput to support many of the most demanding PCIe cards.

The new expansion chassis is suited for use with high-bandwidth networking cards, host bus adapters, and storage interface cards, allowing them to connect with Thunderbolt-enabled iMac, Mac mini, MacBook Air, and MacBook Pro computers, as well as Mac Pro computers that lack PCIe expansion slots. Plus, the Echo Express SEL's dual Thunderbolt 2 ports not only support full-bandwidth connectivity with 20 Gb/sec Thunderbolt 2-equipped host computers, but provide full backward compatibility with 10 Gb/sec Thunderbolt-equipped computers and devices, and support daisy-chaining of other Thunderbolt 2 and Thunderbolt devices.

The Echo Express SEL (part number ECHO-EXP-SEL) is now available for US$399 USD. More information on the product and compatible PCIe expansion cards is available at http://tinyurl.com/na5b6do .