Professional bar adapters from Cannon. TThese handy adapters allow the operator to use the same bar on many different saw makes. The CBW-20045 adaptor plate (S1 to H1) is a 12.1mm to 9mm bar mount. It fits Echo CS7310P saws with bar studs 41mm center to center. Please check your saw before ordering. Important Note: Not all bar mounts are manufactured the same. Some bars may require adjuster holes to be slightly enlarged for bar adjuster tab to fit.