Wireless code lock set - DK-2310 code lock (requires 9 V battery - battery life approx. 1 year for an average of 20 uses per day), compatible with DA-2311 receiver, maximum wireless distance 50m, 4 channels (1-2 -3 outputs and the doorbell), 30 user codes (10 for each channel), 10 visitor codes (for each channel), IP55 DA-2311 wireless receiver with 2 radio transmitters (DA-12), maximum 40 DA- 12 transmitters or DK-2310 radio code lock can be added, 433MHz, 12 -24 V, max. 50m wireless operating distance, 1 relay output, 2 OC outputs, 1 door bell input, 1 opening sensor input, indoor design