Vortex Optics Defender Flip Caps Virtually indestructible, the Defender is the most versatile and durable flip cap on the market, this is the last flip cap you'll ever need. A stainless steel spring flips the cap into multiple stop positions at 45 degrees and 90 degrees. Outside diameter: 48-53 mm | 1.89-2.08 inches Objective-44 Fits: PST-3158, PST-3155, PST-3151, VHS-4305-LR, VHS-4302, VHS-4303, VHS-4304, VHS-4305, VHS-4308, VHS-4309, DBK-10019, DBK-10015, CF2-31013, CF2-31015, CF2-31029, CF2-31031, CF2-31033, CPH-412 Made in the USA