GOHIKING 3-9x42 Hunting Rifle Scope with Integrated Red Sight and P4 Sniper Reticle Innovative center beam technology: first of its kind internal laser sighting System Integrated Red Laser ---The accuracy is also higher than the external and lighter. Open Target Style Turret Knobs are Resettable for easy Zero Recognition Laser Class: Class IIIA. Power: 5mW Hard Anodized Aircraft Grade Aluminum Body.The diameter of needed mount is 25.4mm.