Draper expert 3 4 square drive universal joint draper expert 19604 b i expert quality i b manufactured from chrome vanadium steel hardened tempered chrome plated and polished for corrosion protection hinged head allows drives to swing through 90 176 in both directions spring loaded ball bearing for secure socket holding sold loose br br b manufactured and tested generally in accordance with din3122 and iso3315 specifications b br br draper expert 19604 3 4 square drive u