MadBull Airsoft Barrel Nut Washers

"These are a must have if you purchase any Daniel Defense rails, or any rails in general. The kit came with a total of 6 barrel nut spacers, 2 thicker and 4 thinner. The actual sizes are listed in the description. I had to use the 4 thinner spacers on a lancer tactical upper with the DD M4 4 inch Lite kit, and 1 of the thicker spacers for a 7 inch DD Lite rail on a Krytac upper receiver. These sit on the outer barrel where you tighten down the barrel nut. These eliminate the space between the barrel nut and the outer barrel which is the reason for barrel wobble. Definitely worth the price. I always have a bag or 2 of these on hand, especially for when I do custom builds.