The Wireless Button is like a regular Button (Stone) except that it uses a wireless signal when pressed. By Right Clicking it with a hammer you can access its GUI to select the block which will recieve the signal. Not all blocks are compatible with Wireless Signals (Wireless Redstone 64, PHW Reactor and Indicator Lights can recieve it).

Note: if you link to a Wireless Redstone 64 you will need to manually set it to Output mode or it will not output the signal it recieves.