Trans-Dapt Vacuum Line Cap and Plug Kits are indispensible to any do-it-yourself mechanic. Vacuum Cap kits include: An assortment 1/8" to 3/8" caps. Rubber stopper kits include: 1/8", 3/16", 1/4", 5/16" & 3/8" plugs and 1/8" to 1/2" caps.