994021 STANLEY® Piston Ring Compressor Buy Now 994021 STANLEY® Piston Ring Compressor Buy Now Friction proof edge allows smooth and accurate piston fitting operationSelf locking ratchet pawl prevents premature releaseSuits piston sizes of 2-1/8” to 5” (53-125mm) Additional Features Support Warranty Unfortunately, the warranty information cannot be retrieved for this specific product. Please review the information about our warranties. Learn More Service We take extensive measures to ensure all our products are made to the very highest standards but on the rare occasion that you need our help & support, we've got you covered. Just get in touch. Support Manual STANLEY manuals are available to help put your tools in operation.