A rubber dart washer, also known as an o-ring, is an often overlooked piece of dart equipment by causal and competitive dart players alike, yet they are truly invaluable. Rubber washers help prevent the loosening of metal or alloy shafts by tightly securing the shaft against the barrel, improving stability. Use the Elkadart applicator tool to slide the rubber dart washer over the threads on your dart shaft. Compatible with both steel and soft tip darts. Includes 1 applicator tool and 10 2BA (3/16") sized rubber dart washers/o-rings.