These springs are built to be used regarding super brief big bore dampers (Item 42305) that debuted regarding TRF419X. The set includes 3 different stiffnesss, constantly swiftly change your setup. Brief Spring (smooth) x2 Brief springtime (moderate) x2 Quick Spring (rough) x2 Marking sleeves for difficult (yellow) and soft (red) x2 each Free size: 20mm right for super brief big bore dampers.