Features include solid steel Fire and Rescue Locking
Carabiners that are rated at 10,000 Lbs. capacity each.
They won't wear out like cheap, soft 
aluminum snap-on hooks. Arm slings are
8 1/2" wide with dense and durable 1" thick pads.
Extensively tested in gyms, they've been 
proven to help your back and build a well-chiseled
set of abs!