The xFOB is your personal safety guard at sea. Being placed in the accompanying silicone xBAND the xFOB does not inhibit any movement or motion. Should you fall into the water the engine(s) will stop in just one second. The xFOB fits perfectly inside the wristband. This unique design allows you to decide how you want to use the MOB+ Wireless Cut-Off Switch. The xFOB are made to be universal across all accessories for the MOB+ system.