This auction is for a Teflon chimney and grid collet. The Teflon chimney only fits 3CX800 tubes. The ideal tube diameter is 2.5 inches OD.

The silver plated fingerstock collet fits many tube types. It is an exact fit for grid rings in 3CX800A7 and 4CX150 and 250 style tubes. (I also have sockets.) The collet fits 1.425 inch OD grid rings. It is heavy silver plated copper.