<p style="text-align: left;">When you are lining up a shot, clean functional optics are an absolute necessity! Protect your optics from dust and abrasion with the Monstrum Tactical Flip-Up Rifle Scope Lens Covers. The spring-loaded flip-up mechanism pops open effortlessly when needed and clicks shut when closed. Made of durable rubber and polymer materials, they wont damage the finish of your rifle scope while shielding the lenses from the harsh elements. The Flip-up Lens Cover attaches with a flexible rubber collar that allows each size to fit securely along a range of diameters. It also prevents the lens cover from moving or rotating during shooting.</p> <p>Each package includes one Flip-Up Lens Cover. For optimum fit, carefully measure the diameter of both your rifle scope&rsquo;s eyepiece diameter and objective lens diameter and choose the size from the chart below. <em>Example: if your eyepiece measures 31mm, then you should order Size C so it fits tighter.</em></p> <table class="lensCovers"> <tbody> <tr> <td><strong>Size&nbsp;&nbsp;</strong></td> <td><strong>Diameter (mm)&nbsp;&nbsp;</strong></td> <td><strong>Diameter (in)&nbsp;&nbsp;</strong></td> </tr> <tr style="background: #eee;"> <td>C</td> <td>26-31mm</td> <td>1.02-1.22in</td> </tr> <tr> <td>D</td> <td>31-37mm</td> <td>1.22-1.45in</td> </tr> <tr style="background: #eee;"> <td>E</td> <td>37-43mm</td> <td>1.45-1.69in</td> </tr> <tr> <td>F</td> <td>43-49mm</td> <td>1.69-1.92in</td> </tr> <tr style="background: #eee;"> <td>G</td> <td>49-55mm</td> <td>1.92-2.16in</td> </tr> <tr> <td>H</td> <td>55-62mm</td> <td>2.16-2.44in</td> </tr> </tbody> </table>