Multifunctional Silver M4 40mm Stainless Steel Spring Snap Quick Link Lock Carabiner Pack of 5 material:stainless steel durable and rust resistance dimension is approx 4 x 1.95cm/1.57 x 0.76""(L x W) you can use it for backpack,key ring, chains,ropes,hiking,fishing,indoor and outdoor equipment gear,DIY 5 PCS in one package