This Trend Concealed Decking Jig is designed for professional and DIY use to create a clean, seamless finish on your decking. It features 50° hardened screw guides that create a concealed deck fixing, prolonging the life of your decking and improving its appearance. The jig includes built-in board spacers that create a consistent gap of 3.5mm, 4.5mm, or 5.5mm between boards, ensuring proper drainage and allowing for wood expansion. With a board width adjustment range of 90-150mm, it accommodates a wide variety of standard and non-standard deck boards. The quick-release clamping arm securely fastens the jig to the decking board for easier and more accurate installation. Additionally, it offers on-board tool storage for your driver bit. Works with Trend's Ceramic Coated Deck Screws for installation without visible fasteners. Includes hex shank Robertson no.1 bit driver.