Draper expert 4 piece 1 4 square drive wobble extension bar set draper expert 85136 b i expert quality i b manufactured from chrome vanadium steel hardened tempered chrome plated and polished for corrosion protection spring loaded ball bearing end is flexible which allows bar to swivel for easier access to difficult locations display packed br br b manufactured and tested generally in accordance with din3122 and iso3315 specifications b br br draper 85136 4 piece 1 4 squar