Wera 8100 SA 12 HF Zyklop Metal Switch Socket 1/4" Metric Set 13 Piece The Wera 8100 SA 12 HF Zyklop Metal Switch Socket Set includes the Zyklop Metal Switch Ratchet, designed for working in confined working spaces. It has an extra-slim design for access where conventional ratchets cannot operate; with a longer length Wera 003756 - 8100 SA 12 HF Zyklop Metal Ratchet Set push-through