Draper expert 30mm drive 75mm vortex extension bar draper expert 78903 expert quality manufactured from chrome vanadium steel hardened tempered chrome plated and polished for corrosion protection for use with the draper expert vortex system display packedmanufactured and tested generally in accordance with din3122 and iso3315 specifications draper expert 78903 20mm drive 75mm vortex extension bar