The all new HD-Micro from Ultradot is a high quality sight engineered to give you the smaller size and weight of an open style sight with the strength and durability of a tube model. It boasts many new features never before seen on an Ultradot product like: PWM circuitry Auto-Off Push Button Brightness Adjustment Brightness Memory Precise 2 MOA Dot Size and a Built-in Rail Clamp System. Don't let its small size fool you. This is one tough sight and is backed by our Limited Lifetime Warranty. - Tube diameter: 28mm - Dimensions: 90.5 X 50mm - Weight: 140g - Battery: CR1620 3V Lithium - Windage adjustment range: 356cm @ 100m - Elevation adjustment range: 356cm @ 100m - Click adjustment: 2cm @100m - Dot size: 2 MOA - Dot brightness adjustment: 10 settings - Parallax Free @ 100m - Shock proof: 1500g - Waterproof: Immersible @ 5m