Sep 11 14:17:34 Pikachu /kernel: ums0: Logitech USB Receiver, rev 1.10/9.10, addr 4, iclass 3/1 
Sep 11 14:17:34 Pikachu /kernel: ums0: 5 buttons and Z dir. 

port 2 addr 4: low speed, power 50 mA, config 1, USB Receiver(0xc501), Logitech(0x046d), rev 9.10