The DeepSee Viewer takes discovery and exploration to a new level by bringing you closer to what’s inside the tank. See what you’ve been missing with a DeepSee Viewer. Magnified Magnetic Aquarium DeepSee viewer is safe for both glass and acrylic tanks Great for discovery or checking for signs of disease or pests on coral or fish Optical-grade magnifying lens with a 4" viewing portal is perfect for photography A focal range is approximately 3 to 8 inches Secured by a strong rare earth magnet for tanks with walls up to 5/8" (16mm) Easily moves around the tank for viewing from any location Suitable for all tanks - freshwater, saltwater, or terrariums Actual Item Dimensions: 5.9" x 4.1" x 0.5"