1)wireless doo rbell with hearing aid. 2)Frequency: 1800-1900 MHz 3)For the aged. 4) CE 5) Water proof with IP65 wireless ... door bell with hearing aid, CL-6011 Technical Specifications1 ... unit4,Use the handset to unlock the door5,Volume adjustment6,Flash LED indicate a call incoming even on Mute status7,Hearing Aid speaker, easy ...