The ANSI-rated RED Back-Up Device, with its positively locking springs, allow it to self-park (instead of self-tail) to maintain the best position to reduce fall factors in case of a fall. The Popper Tow Cord has a break-away clip which assists in smooth descents, and releases (pops off) in a panic situation. Weight: 210 grams (7 ounces) Strength: 140kg (310lbs) for single load. 240kg (530lbs) for rescue (2-person) loads For single ropes from 10.5 - 11mm (3/8" - 7/16") Making use of 'Rotational Braking'- the more the device rotates clockwise, the greater the build up of friction, which provides the automatic braking in the event of a fall or sudden pull on Popper Cord. Certifications: CE EN12841, ANSI Z359.1