Meopta has a couple optics that are not available in the US at the moment. No idea if Meopta USA will be carrying them but they look cool.
First up is the ZD-Dot. According to their website:
ZD-Dot red dot sight is a ruggedized and shock-proof tool suitable for any automatic rifle. Electronic regulation of the red dot intensity allows 10 intensity levels for day and night. Enhanced optical parameters eliminate reflection, astigmatism and both vertical and horizontal parallax. The unit is powered by one AA battery.
The Meopta catalog says the ZD-Dot can use any AA battery within the volt range of 1.2 – 3.6v. I find that very interesting. In some of my flashlights, I use Li-Ion rechargeables called 14500s. The 14500 is a rechargeable AA sized battery but puts out 3.6v. Your run of the mill disposable li-ion Energizer AAs are still just 1.5v.
Here they are combined on a CZ BREN.