The Quick Jam is a sturdy door jammer made from strong 1.250 inch carbon fiber tube. The hook attachments are made from stainless steel. The Quick Jam has a push button slide adjusment nut on each end. The attachment hooks extend thru the middle of a thick rubber bumper to avoid damage and tool marks to your customers cars. The Quick Jam is 12 inches bewteen the hook to hold the door open at an optimal distance and rock soild for fast and easy repairs. To use The Quick Jam simply hook the striker and slide the end piece snug, then insert the latch hook into the door and slide snug. Then, if needed, give a twist to both sliding adjustment nuts to desired tightness. Fastest jammer on the planet!