<http://schema.org/description>
"Sheaves are 40mm (1-1/2 inch) precision molded U.V. stabilized Acetal with Acetal ball bearings and support a max line size of 3/8 in (9.5mm). The pin diameter on these blocks is 3/16 in. Use these blocks for vangs, backstays, cunninghams, traveler controls, furling line leads and main/jib/spinnaker sheets. Work well for mainsheet, jib sheet, and control line situations on boats up to 26 feet. Ronstan Series 40 Blocks are incredibly strong for their size."^^<http://www.w3.org/2001/XMLSchema#string>
<http://www.apsltd.com/series-40mm-double.html>