These come in a pack of 10.

A very small (only 4 grams) 125 KHz high security digitally encrypted proximity key tag. It has a hole for a key ring or chain. It is pre-programmed at the factory with a unique encryption code. It is small and durable enough to fit on a key ring. It provides a read range up to 2 inches.

Requires an Ethernet-enabled HAI controller that has firmware version 3.0 or higher.