waiter call system. simple but powerful many master station and call extension available used many fileds,like hospital, Water call system of features:Three 2.0 inch LED digitals, the material is ABS;With 4 keys, power: 12V1A, display A,B,C,D,H,L,P,U letters;With remote control, cancel calling automatically or manually, checking calling records;The capacity of calling is 200, 10 calling button ...