RockJock's Billet Aluminum Antirock Sway Bar Arms are beautifully constructed, yet offer race quality strength for aggressive off road applications! Made entirely in house on their own machines, they start with premium 7075T6 aluminum material, CNC machine the arms to shape, CNC machine the pocketed design and the logo etchings, broach the 25 splines and finish them off in clear anodizing! These specific arms are 21 in. long from tip to tip, 3/4 in. thick (with the exception of the tip being machined to 3/8 in. thick for end link mounting). At the arm mounting end, you'll find RockJock's standard 25 spline that fits all common Antirock torsion bars as well as our high-end, 12-point vertical pinch bolt and nut. RockJock's billet aluminum finishing washers and flat head allen bolts that thread into the end of the sway bar torsion bar are also included. At the end link mounting end, the arms trim down to 3/8 in. thick and you'll find two 1/2 in. Sway Bar End Link mounting holes that allow you to adjust end link mounting position to increase or decrease leverage on the torsion bar. These 2 holes are commonly used in conjunction with RockJock's RJ-201000-101 Double Sheer End Link Bracket Kit.