Malco FCG2 1-1/4 Inch Overlap 5/16-Inch Thickness Fiber Cement Siding Gauge, 2-Pack Allows 1-person installation of siding planks Two gauges support the entire length of plank and precisely gauge a standard 1-1/4-Inch overlap - even on a bowed wall No adjustments to vary and nothing to mark Works on old or new 5/16-Inch fiber cement siding plank Will not mar finish of pre-painted siding Made in the USA