1.gas spring, chair gas spring, gas lift 2.competitive price 3.high quality 4.SGS BIFMA 5. ... Up & Down 100,000 times ProductsDescriptionNameGas spring/gas lift/gas cylinder/gas strutUseUsed for boss chair/ office chair/bar ... medium tube & outer tube.Class 1---1.2mm, cheaper price, two year warranty(Normal)Class 2---1.5mm, cheaper price, three ...