Nepros Adjustable Wrench Made in Japan To facilitate use, the nepros adjustable wrench (NWM-250) angles the opening of its adjustable head at a 15 angle  the same used on our standard open-end wrenches. he thick grip offers a balanced design that also contributes to ease of use. Rattling of the sliding jaw is almost nonexistent, and the worm gear movement is smooth. Easy-to-read scales are featured on both sides.