The KSK301A is a 2 Relay Stainless steel vandal resistant backlit keypad that is IP66 rated, and requires 12v-24v AC/DC power. It has the capacity for 1000 User codes on relay 1 and 100 user codes for relay 2. Both relays can be adjusted from 1 second to 99,999 Seconds or toggle mode. The KSK301A has electric blue back lit buttons and 3 indication lights for access granted,access denied, and Programming mode. And is ideal for internal or external use.