Two-piece base sets, CNC machined to exacting tolerances, provide rock solid scope mounting. Reversible and long rear bases make it easy to use standard rings to mount scopes, from extra long varmint and target models to small compacts on any length action. Front bases accept Leupold’s (and Burris/Redfield/Millett) rotary dovetail ring. The rear base uses standard Leupold/Burris/Redfield/Millett windage, screw-secured ring.