VW 1600 Based Type 1, 2 And 3 Hi Perf Aluminum Push Rod Tubes With Seals. Tube can be machined to fit narrower engines. Two piece spring tension tubes expand and contract as the engine heats and cools, with dual o-ring seals between the tubes and stock style tube seals at each end. Has a 7/8" inner diameter at the head for optimum push rod clearance. Sold each or in sets of 8. Replacement o-rings also available.