Standard Description Class is different from the thickness of medium&outer tube.
Class1 1.2mm thickness 3 years warranty Class2 1.5mm thickness 3 years warranty Class3 2.0mm thickness 5 years warranty Class4 2.5mm thickness 5 years warranty
Application and Features
Gas spring, gas lift, gas piston, gas cylinder, gas strut for all kinds chairs Boss chair gas spring:40mm, 60mm, 80mm Office chair gas spring:100mm, 120mm, 140mm Bar chair gas spring:160mm, 180mm, 200mm, 260mm, 330mm