PacTool SA902A.01 Gecko Gauge 2-Piece Aluminum Fiber Cement Siding Gauges Designed for use with 5/8-inch James Hardie Artisan Lap siding products. Adjusts for 4-inch, 6-inch and 7-inch James Hardie Artisan Friction-Cam mechanism for incrediable holding power Super-durable aluminum construction Gauges and supports fiber-cement siding for one-person installation with virtually no layout time.