Master space controller (Kramer Control brain) that can operate over Ethernet with control interfaces that include: eight bidirectional RS−232, eight IR, eight GPI/O, and eight relays.
Amazon.com: PlayStation 2 Guitar Hero Wireless Kramer Striker Controller : Video Games
Kramer Control Cloud-Based Control Platform | AV Australia Online
Official Wireless Guitar Hero Kramer Guitar Controller (PS2) : Amazon.co.uk: PC & Video Games