Jewell gas spring company is the professional manugacturer which specialied in producing air spring 1.air spring ,it is a kind of spring which is used to adjust the position.It gets the certificates of LGA ,SGS and TUV. 2.All types of gas springs Our Gas springs are applied on vehicles tailgates and bonnets,bus baggage lids and seats,caravan-lids,tractor cabins, folding beds, office-chairs,roof ...