With this kit you can easily mount hairsprings on your frame. The set consists of two bungs that you can weld to the frame, 2 Stainless steel M8 Allen bolts with round head and 2 stainless steel washers. The bungs fit on a frame tube 1'' (Ø25, 4mm) but they are also easy to adjust to fit on a larger diameter tube. 

Material: Good weldable steel!