9Pcs Serpentine Key Belt Tension Kit Pulley Alignment Key Tool

Features:
Professional tool for daily commercial or occasional DIY use.
Releases tension on coil belts with the most inactive pulley loaded spring.
This assembly makes changing serpentine accessory belts easy even in tight spaces.
Fits more inactive pulleys that require 15mm, 16mm or 18mm hex and 3/8 or 1/2 square units.
Comes with a mould box for easy storage and carry.