This tool is designed to break roller chains up to 630 series and fits all standard and O-ring chain sizes 520, 530 and 630. The tool rivet chains up to 530. Master link side plate press kit is included to press-fit side plates on chains up to 530. The screws and attachments of the tool are heat treated for strength and durability. The extractor pin is precisely guided by a removable guide ensuring long pin life. The tool may be bolted to a workbench, supported in a vise, or held by handle. When bolted to a solid surface, air or electric wrenches may be used to break chain. This jumbo chain tool is recommended for heavy-duty use. Instructions are included.