3 d - See translate

Discover the Benefits of Nut Retainers which are self-retaining and cannot turn as the bolt is tightened, resulting in positive, high-torque attachment. Bolt Products, nut retainers and bolt retainers combine the best advantages of spring steel fasteners with the unparalleled fastening strength of a multi-threaded nut.
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https://www.boltproducts.com/n....ut-retainers-c-700_2

Reliable Assembly with Retaining Nuts | High-Quality Fasteners for Stability