Used to press bearing neck cup into the frame neck and bearing races into the cups. Neck cups can be as much as a .004"-.006" interference fit. That's why it takes a big hammer when you install them that way. This tool gently presses them in like butter without damage or uncontrollable forces. - Makes easy work of installing neck cups & races into motorcycle frames - Incorporates unique thrust bearing system - Critical components made from steel alloy that has roughly double the tensile strength of mild carbon steel - Quick-adjustable length to work with a wide variety of H-D, aftermarket, and custom made frames - Comes with 2 anvils that work with all H-D neck cups that are the tapered roller bearing type - If you have an oddball motorcycle and the anvils don't fit your cups, the adjustable length allows you to make extra spacers that better fit your cups - Cerakote finish - USA made. Note: Fast Eddy advises you to only press cups in your frame that already have pre-installed races. Or press new races into the cups at the same time you're pressing the cups into the frame. Do not press cups into the frame without bearing races. / Fitment: 49-84 FL, FX, FXWG; 84-86 Softail; Custom frames with H-D style frame neck cups