Rosewill RNX-N300 802.11b/g/n Wireless-N PCI Card for $19.99 Shipped

Rosewill RNX-N300 802.11b/g/n Wireless-N PCI Card for $19.99 shipped after promo code EMCLTNP59.  Here is a screenshot for your reference.  It is backward-compatible with 802.11b/g and supports up to 150Mbps in 802.11/n mode.  Most places have it for about $32.