The Locknut Wrench has been designed to end frustration! This perfect tool for locknut operation fits the majority of UL locknuts and features a thin profile that makes those normally tight spaces a thing of the past. It can be used to loosen or tighten a locknut by rotating the wrench in the direction of the arrows marked on both ends. The GB Locknut Wrench is the perfect reliable and durable addition to any tool box. Durable steel construction , Fits majority of UL locknuts , Thin design allows easy maneuvering in tight locations , Hooked tip latches onto locknut and maximizes turning leverage, Etched markings allow for easy identification.