Alignment slot to tighten and loosen most pole hardware|Engineered for use with impact drivers|Fine tuned ball detent provides improved retention, minimizing drops|The Klein Tools versatile 3-in-1 impact socket is a must have for linemen and utility workers|It features three popular square sizes that can be quickly and easily converted for a variety of utility type applications|5-in-1 Impact Socket features three square socket sizes- 3/4 in, 1 in and 1-1/8 in, and small and large alignment slots|13/16 in diameter, 6 in (15.2 cm) long hollow shaft allows use on long threaded bolts