Use with Fasco 11356F Tool or Tiger Claw F-5899-igun •Use with Fasco I-Clip or •930 Scrail fasteners per box covers approximately 500 square of decking •Fastener needed at every intersection of joist and deck board •InvisiDeck system automatically creates 3/16-Inch space between each deck board Fasco SCPS413FPFCB Hidden Scrail Fastener for installing grooved deck material. Works with Fasco 11365F tool or Tiger Claw F-5899-igun and Fasco I-Clips. 1 box contains 930 scrails that will cover approximately 500 square feet of grooved decking. Fasco SlotCutter can be used to create appropriate groove. Fasteners can be backed out like traditional screws.