A-B123139GS-AI KEY-SQUARE model-942536J It is a wrapped polyester

It is a wrapped polyester cord V-belt used to transfer power from the tractor PTO to the mower deck spindle assembly

This pack includes four #80 roller chain connector links (also known as master links)

Fits Pro: 7523015

Replaces Part Number(s): B51776

A-B123139GS-AI KEY-SQUARE model-942536J It is a wrapped polyesterOne New Aftermarket Replacement Square Key Fits Briggs and Stratton (Fits Briggs & Fits Stratton) Small Engines This square key is a small but essential drivetrain component used on Fits Briggs and Stratton engines. It seats into the keyway on the crankshaft or pump drive shaft, locking rotating components in precise alignment and preventing slippage during operation. Commonly used on pressure washers, lawn mowers, and other outdoor power equipment