It is lightweight and easy to handle,durable and does not rust. Each ring is securely attached to a metal loop, very easy to separate and carry. Ring Sizer Mandrel is made of aluminium. The 26 Pieces ring sizer set is made of steel. Comfortable to wear, no worry to cut your fingers. Clear to read and accurately measure the ring size. Ideal for both personal and professional use, perfect for fitting wedding rings, class rings and other wide rings.