Designed to increase installation speed of popular engineered wood panels while meeting manufacturer's specifications. Provides the correct nail placement consistently while reducing reliance on acute eye-to-hand coordination. - Allows variability in gun angle while still landing in the “best practices” fastener zone. - Spring loaded pin allows normal use of the nailer. - Anodized finish - Hex key included - Stainless steel set screws. EW gauge models are design to place nail 3/4" from edge. EW4 Fits: (OD 0.75″ to 0.76″) Senco: SCN49XP, SCN49FRH, SN71P1, SCN49. Pneutools CN65Z, Grip Rite GRTCS250Z, Paslode tetraGRIP TG100CSN, Paslode CE20024, Metabo NV75A5 (tight fit), *** Note: While other nail guns/nailers may be compatible, listed above are the only ones known to fit. *** Check WellsDesignToolco.com for up to date list of compatible siding nailers.