Sleek & powerful the MAD Key Fob Chargers provide a quick charge for your smart phone on the go. Securely attach Key Fob Charger to your car keys with durable carabiner. The Key Fob Charger will not add bulk to your keys. Easily recharge key fob with USB & wall charger. USB & micro USB port included on device. Mad Man, masters of men's gifts. Material: Silicone/Alloy. Dimensions: 1.5" x 3"