Our Spade Solvent Trap Tube Built in 2.5'' Spacer , with 1/2-28 and 5/8-24 Thread . Our Trap Send With Small Allen Wrench , as Gift to open the end cap . It can use for our Piston Booster Kit . 1/2x28, .5/8x24, 578x28, 9/16x24, 13.5x1LH availabl Industry standard thread are 1-3/16x24 .This is American Standard , Very popular in the U.S. market. Our Product are exquisitely crafted and do not have a center mark. Please see the picture..syi