We have improved the SWH series plastic TableTop chains by upgrading the classic helical knurl to a new helical knurl pin design. Old and new chains can be coupled. The old and new design will run on the same sprockets and tracks. All characteristics remain the same. The old pin version will continue to be produced until the end of February 2012. The new version will be provided with upgraded pin design in March 2012. Pricing and delivery will remain the same.