Wera 8794 Zyklop VDE Extension Bars - 3/8in. Square Drive - Wera 05004964001, This Wera 8794 SB VDE Zyklop 3/8in. square drive extension bar is individually tested as per IEC 60900 at 10,000V for safe working at the approved voltage of 1000V.It offers increased safety over other VDE extension bars due to its yellow insulation core which becomes visible if the outer red insulation layer is damaged. Wera 05004964001 8794 SB Zyklop VDE Short Extension 3/8\" Drive 3/8\" x 91mm