These large mouth concrete manhole housing lifting clamps are designed to handle 4" to 6" thick sections without damaging the concrete seat. Lifters work on a variety of housing shapes and chain legs allow for quick positioning to balance the load. Concrete housing lift attachments require constant tension to maintain positive load contact, while reverse cam action design eliminates load slippage tendency. Heavy duty steel construction and clamps have a durable enamel finish. Meets ASME B30.9 & B30.20 standards.