spring balancer also named tools balancer, power master, zero gravity tools balancer, load balancer retractor and so on names. Spring tools balancer capacity from 1 kg to 400 kg, stroke is 1.5 meters to 3.0 meters. Our Zero gravity tools balancer more durable than others, have strong wire rope on it, and for safe, on the top and bottom both have the safe chain system. If you don not know how to choose the spring retractor, or want to know how to use the spring tools balancer, or want to buy the zero gravity tools balancer, please contact with us. professionally service want to get your satisfaction. Shan Dong Finer Lifting Tools co.,LTD Email:sales@cargotrolley.com http://www.cargotrolley.com/