The Proform 66766 is an adjustable piston ring compressor designed to simplify piston installation for engines with bore sizes ranging from 4.000 inches to 4.090 inches. Its precision-machined aluminum construction and anodized blue finish offer durability, corrosion resistance, and ease of use in professional or home engine-building environments.

Key Features:

• Adjustable to fit 4.000" to 4.090" bore sizes
• Smooth, even compression of piston rings for easy and safe piston installation
• Precision-machined from high-strength aluminum
• Blue anodized finish resists wear and corrosion
• Lightweight and compact for easy handling and storage
• Ideal for repeated use in professional or DIY applications

Specifications:

• Material: Aluminum
• Finish: Blue anodized
• Bore Size Compatibility: 4.000" to 4.090"
• Tool Type: Adjustable ring compressor
• Weight: Approx. 0.5 lbs

Applications:
Ideal for performance engine builders, race shops, or garage enthusiasts working on engines within the specified bore range. This tool ensures precise piston installation with reduced risk of ring damage.