Detailed DescriptionSIA Abrasives 7900 SiaNet Sanding Discs 6" [150mm] P180 Grit x50 Discs to be used Orbital Machines Attached with the Hook'N'Loop System Grit type: Blue-fired aluminium oxide /white aluminium oxide.The Quality SIA Abrasive 7900 sanding discs are a net-backed abrasive sanding discs with minimal clogging, high removal rate and high tear resistance. No dependence on hole system. Ideal sanding down coatings and impurities, sanding out unevenness at the edges of repaired surfaces and for fine sanding.