The heavy-duty key ring lets you carry much heavier items; you can lock the ring end of its cord into a socket in its body. It has a 1-1/2" split ring and a spring-steel belt clip that you can convert to a 1-3/4" wide closed belt loop using an included pin.
The carabiner key ring has a 1-1/4" split ring and a sturdy spring-loaded clip for quick and secure attachment to a belt loop or backpack strap. It can hold up to 10 oz. The body of the carabiner key ring is 2" in diameter; the body of the heavy-duty key ring is 2-1/8" wide and 2-5/8" long.