Product Description: TP-Link TL-WN721N Wireless Lite N USB Adapter - network adapter
Device Type: Network adapter
Form Factor: External
Interface (Bus) Type: Hi-Speed USB
Dimensions (WxDxH): 8.7 cm x 2.4 cm x 1 cm
Data Link Protocol: IEEE 802.11b, IEEE 802.11g, IEEE 802.11n (draft)
Data Transfer Rate: 150 Mbps
Frequency Band: 2.4 GHz
Compliant Standards: IEEE 802.11b, IEEE 802.11g, IEEE 802.1x, IEEE 802.11n (draft)
System Requirements: Microsoft Windows Vista / 2000 / XP
Microsoft Certification: Compatible with Windows 7
Yes! It is only 150Mbps but then at £4.12 delivered it is at least £2 ahead of the nearest competition including delivery.
Cheap enough to stick it in your computer bag for those "just in case" situations.