Aim-O RD-2 Open Red Dot — Black

The RD-2 is an open-tube red dot from Aim-O designed for shooters who want a always-ready sight on a handgun or short-barrelled rifle without the bulk of closed housings. At 150 g it sits among the lighter options in its category, keeping balance shift minimal even on already well-balanced builds.

The open-tube design delivers fast target acquisition: the eye finds the dot naturally even from imperfect presentations, because there is no housing restricting the peripheral field of view. The trade-off worth knowing is that this same openness exposes the internal optics to dust and moisture more than a sealed body would: on a range or in controlled environments that means a cleaner sight picture, but in heavy rain or submersion it is a factor to weigh. Power comes from a single CR1632 coin cell, a widely available flat-format battery not included in the box.

The open-tube construction also simplifies maintenance: lens cleaning is straightforward and requires no disassembly. For the shooter looking for a day-to-day optic on a handgun or carbine, the RD-2 offers a balance of size, weight and target-acquisition speed that suits both dynamic shooting and defensive use.

Key points

• At 150 g it does not shift the balance of the firearm — relevant on pistols and lightweight carbines.
• The open profile speeds up target acquisition: no housing limits the peripheral field of view.
• Lens cleaning and maintenance are straightforward thanks to direct access without disassembly.
• Powered by a widely available CR1632 coin cell — no proprietary battery required.
• Compact design suited for mounting on handguns, carbines and short-barrelled rifles with standard rails.

In the box

• Aim-O RD-2 collimator