«………The JCS 6 inch long 3/8 dovetail rail for 3/8 dovetails fits any marker with a 3/8 dovetail. This sight mounting rail is precision machine black anodized aluminum. Designed to mount in a variety of configurations this rail offsets 5/8 or 1 inch off center so you can see around vertical feed hoppers. JCS Performance Upgrade. Requires 1 Phillips Screwdriver for installation……..»