The ERGO Accurizing Wedge eliminates play between an AR-15's lower receiver and upper receiver. The wedge is easily installed by removing the rear take-down pin and inserting the wedge into the rear of the receiver. The wedge can easily be trimmed for a perfect fit in your AR-15. ***BBR Tip: These are also great for tightening up the fit between upper and lower on your AR build when you use different manufacturer's parts. Your "Frankengun" will fit much tighter and won't have that annoying play or wobble between the receivers.***
