What you get - A protective lens cap designed to guard telescope optics from dust, scratches and moisture when not in use or during transport. Key benefits - Measures the exact inner diameter (aperture) to match your telescope outer diameter, preventing gaps and slippage. - Protects delicate lens surfaces during storage, transit, or maintenance. - Durable and reliable plastic construction for everyday use. - Lens caps are sold individually, allowing you to replace or mix sizes as needed. fit and compatibility - Aperture size is the inner size of the cap and also the outer diameter of the telescope; measure your telescope diameter before purchasing. - Caliber options (inner diameters): 25.5 mm, 28 mm, 30 mm, 34 mm, 35 mm, 36 mm, 37 mm, 38 mm, 39 mm, 40 mm, 41 mm, 42 mm, 43 mm, 44 mm, 45 mm, 46 mm, 47 mm, 48 mm, 49 mm, 50 mm, 51 mm, 53 mm, 57 mm, 58 mm, 59 mm, 60 mm, 61 mm, 62 mm, 64 mm, 65 mm, 66 mm, 67 mm, 69 mm. material and durability - Made of high-quality plastic material, durable and not easy to break. usage scenarios - Field setup: snap on to protect the lens end during moves between locations or when stacking equipment in a travel case. - Storage at home or in a dome: keep dust and moisture away from optics when equipment is not in use. - Maintenance or equipment swaps: quickly replace caps on different telescope models without tools. care and maintenance - Clean with a soft, dry cloth to remove dust. - Inspect for fit and seal periodically to ensure ongoing protection. note - Please ensure you select the exact inner diameter that matches your telescope outer diameter. If exact size is not available, choose the closest match from the listed calibers.