Tapered Fit, Screw on Pile. These are my own pile of choice. I just taper the shaft and screw them on. No glue is needed. Having used these piles for over 2 years with no glue I haven't had a single one come off in a target. The lack of glue comes in very handy when you plant your arrow into an innocent tree or buried tree root. If it's not possible to easily extract the arrow I simply unscrew the shaft and sacrifice the pile but save the arrow.