Great Scott Gadgets Ubertooth One, Antenna & Aluminum Enclosure Bundle by Nooelec;

This Ubertooth bundle includes everything you need to get started with development, including the Ubertooth module installed into a protective, shielded aluminum enclosure and a 2.4GHz antenna.

The Ubertooth One is an open source 2.4 GHz wireless development platform suitable for 2.4GHz experimentation. Based on the powerful LPC175x ARM Cortex-M3 microcontroller with full-speed USB 2.0, the Ubertooth One is a great way to develop custom Class 1 devices. The entire board is only two and a half inches long with a USB-A connector at one end and an RP-SMA connector at the other.

One thing that sets the Ubertooth apart from other 2.4GHz development platforms is that it's capable of not only sending and receiving 2.4 GHz signals, but can also operate in monitor mode, monitoring traffic in real-time. This operating mode has been present in low-cost WiFi modules for years and has found myriad uses in research, development and security auditing but no such solution existed for 2.4GHz standards until now.

Also, because it's a fully open-source platform (software and hardware), the schematics and code are readily available for all of your hacking needs.

Dimensions: 61.75mm x 19mm (2.43" x 0.75")