Play your favorite song and pump up the volume while swimming in open water. With IPX7 certification you can install HMC U1 remote control anywhere on the boat. Optional for CAPRI, HMR 50, HMR 20, HMR 18, HMR 18D, HMR 15, HMR 15 D, HMR 10 D, HMR 10, HMR BT.