New at the SHOT Show in 2015 are the flip-up back-up sights from Meprolight. The Mepro M2D and M4D front and rear sights are rail-mounted and fully adjustable. Taking things to the next level, however, is the incorporation of tritium to the equation, making the back-up sights fully usable even in complete darkness.

The rear sight has four tritium dots to be used to center the front post tritium, making the sights always ready and maintenance free. Meprolight gives a 10-year...