5/16" Lock Nut

Listed on the following equipment:
Nautilus Commercial (Core Fitness) - Bicep Curl - S3BC
Nautilus Commercial (Core Fitness) - Dual Stack Freedom Trainer - F3FTD
Nautilus Commercial (Core Fitness) - Human Sport Arm Crunch - HSAC3 - Gen 3
Nautilus Commercial (Core Fitness) - Leg curl - S6LC
Nautilus Commercial (Core Fitness) - Leg extension - S6LE
Nautilus Commercial (Core Fitness) - P3GH - Nitro XPLoad Glute/Ham
Nautilus Commercial (Core Fitness) - Single Stack Freedom Trainer - F3FT

* Images may not be identical to part.