These are self tapping screws made for fastening to a wood substrate. They are capable of going through the starter holes of our polycarbonate snow guards but most people find it easier to drill out the starter points before going on the roof. The Snojax I and SnowBreaker models already have pre-drilled holes for screws.
The Master Driller and the Master Gripper screws come with a pre-attached metal washer with neoprene rubber installed under the head of the screw.