High vacuum inner joints have a groove above the ground zone for a Viton O-ring. This forms a vacuum-tight seal when used with a mating outer joint. No lubricants are required-twist to assemble or disassemble. Supplied with a Viton O-ring.
100% Satisfaction Guarantee: At Mansion Labs, we want to be sure that the item you choose is the right one for you. Within 30 days of delivery of your order, you may return any merchandise purchased from Mansion Labs in its original condition with your email order confirmation or packing slip. Restocking fees may apply. On items over $275 shipping within the US, we will even arrange free pick up or pay for returns shipping.