Target Scope Base .275" Height for mounting target sights or external adjustment scopes on long range rifles. Versatile, steel base accepts target front sights and external adjustment scopes from Redfield, Lyman, Unertl, Malcolm and others that require a 3/8" dovetail base. Contoured bottom radius provides a tight, solid fit to barrel, prevents side movement and ensures base is aligned squarely with receiver. Does not fit Redfield external adjustment scopes. Specs-1018 steel, matte blue finish, 1-15/16" (3.5cm) long, 9/16" bottom radius, hole spacings are .860" and .562". Includes 6-48 screws. Made in the USA.