This is a Ultradot Red Dot known as the Ultradot 30, model UD30B.
The Ultradot 30 is only 5.1 inches long and weighs just 4.1 oz. 30mm diameter tube and click adjustable brightness control. Every sight comes complete with a battery" polarizing filter" tube extension" mounting rings and hex wrenches. Every Ultradot sight has a LIFETIME WARRANTY.
Features:
4 MOA dot
Compact size
Click adjustable brightness control
1 MOA per click adjustments
11 brightness settings