- What it is: a 47mm cylinder piston bolt ring replacement for garden chain saws, designed to restore proper piston movement and compression. - Compatibility: fits 47mm cylinder piston bolt ring for models 2159 CS, 2156 CS, 2159, 357, and 359. - Why you need it: worn or damaged rings reduce compression, power, and reliability. Replacing with a correct 47mm ring prevents piston binding and costly engine damage. - Key benefits: precise 47mm fit that meets original specifications, supports durable and reliable operation, easy to install during standard maintenance, helps keep saw performance consistent. - Practical applications: - Regular maintenance on 2159 CS or 2156 CS to restore power and smooth operation. - During a rebuild or piston service on 2159, 357, or 359 to ensure correct compression. - By repair shops performing field service to deliver accurate, ready-to-install replacement parts. - Performance note: designed to maintain engine timing and compression, contributing to longer service life and dependable starts.