Material: Steel For roller shutter profile 37, 45, 55, 77mm Name: Spring for roller shutterMaterial: steelItem No.: MAR0309-130Size: 100*130mmFor roller shutter profile 37, 45mmItem No.: MAR0309-190Size: 120*190mmFor roller shtter profile 55, 77mm Spring for roller shutter/Connecting belt for rolling shutter