... support products, is the advanced materials for underground culvert roof and other projects supporting,manufacturing processes with a simple way, ... easy to use, has strong anchor,large tensile strength and strong expansion force in the underground .Diameter:33mm,39mm,40mm ... 150 x 150 x 5mm,200 x 200 x 10mmDiameter and length can be customized according to customers’ requirements. split set rock bolts, ...