ThinkPenguin TPE-N150USB

ThinkPenguin's product page

Dimensions (L x W x H), per ThinkPenguin, are Dimensions::30 mm x 17 mm x 8.5 mm.

This device is FSF-certified.
 * FSF Certifies Atheros-Based ThinkPenguin 802.11 N USB Adapter on Slashdot
 * A thread on /r/linux about the device.. and another (plus another one on /r/gnu)

Output of sudo lsusb -v -d 0cf3:9271 here, or here.