Pls note KNZD-05 have 4 versions: KNZD-05N: Normal phone, make call as normal desk type phone. Without Speed-dial function KNZD-05A: Auto-dial phone. As soon as you pick up handset the phone will put through. The keypad only for storing 1 group number purpose. After finish program number the keypad will not perform till you switch main PCB board. KNZD-05B: Speed-dial phone. The keypad can store 15 group of number on each button. When pick up handset need to select one button to make phone call. KNZD-05C: Speed-dial phone and normal phone call. This phone can make normal out going phone call and also S1, S2, S3, S4 can store 4 groups of speed-dial phone number. Applications: As Public telephone for indoor or outdoor, Taxi or bus stands or station, Highway call box Railway, metro, ATM machines side, Tunnel, Port, Dock, Mines, Generation facilities¡K. A good ideal telephone for use in wet or corrosive atmospheres