Key Chain：
Easy to carry
Suitable for people usage

Carabiner：
Easy to attach
Suitable for tagging asset

Lithium Coin Battery：
Easy to replace
Easy to find in the market (CR2325)
Suitable for long term usage

Card Holder/ Badge：
Vertical / Horizontal
Can be used with the exiting staff card/proximity card
No interference
Will not affect the existing system

Silicone Case：
More Durable
Better covering and protection
Water proof, prevent shower directly (IP54)