1,OEM/ODM double tension spring,air spring 2,different surface treatment 3,steel material 4,Zn or other coating

All double tension spring can be customized.

spring roll,spring loaded in,torsion wire spring,slinky spring,gas spring arm,spring plunger,spring hose,diaphragm spring clutch,flat torsion spring

All spring  produce  as your require.rates and compress length,low density,high specific strenth,excellent corrosion resistance,rustless

All kinds of surface treatments are available: polishing, zinc plating, nickel plating, chrome plating, powder coating, 

Chritmas use OEM/ODM double air spring