VERSATILE INTERCHANGEABLE INSERTS ALLOW THE SHOOTER TO CUSTOMIZE PEEP FOR PREFERRED SIZE/COLOR(PATENT PENDING). LIGHTWEIGHT ALUMINUM CONSTRUCTION. PRECISION CNC-MACHINED. METAL PEEP SIGHT IS 1/4″ DIA. WITHOUT INSERT. ANGLED DESIGN FOR SHORTER AXLE-TO-AXLE BOWS. INSERTS INCLUDED ARE 1/8″, 5/32″ or 3/16″. INSERT COLORS INCLUDED ARE BLACK,WHITE,AND BLUE.