This is something we've been waiting for. We finally have access to the Schumacher ArmSafe kits. It's used to prevent an electric motor from injuring the pilot if the throttle is bumped while he's still putting the hatch cover or canopy on his airplane. It goes between the ESC and battery. Only when the Deans key is inserted does the circuit complete, and the ESC turns on.
This ArmSafe kit is as essential a safety device on larger electric planes as a range check is. The kit runs $14.99 and is in stock now.