As the name suggests, the Trijicon RMR (Ruggedized Miniature Reflex) is both tough and small. Housed in forged aircraft-grade aluminum, it is also lightweight, and all RMRs are rated waterproof to pressures equivalent to depths of 66 feet. The Trijicon RMR is available in three models with different reticle patterns. The first is the LED version, which is available in a 3.25-m.o.a. red dot and an 8-m.o.a. red dot. The second model is the Dual-Illuminated, which currently is available with one of four reticles: a 13-m.o.a. amber dot, a 7-m.o.a. amber dot, a 9-m.o.a. amber dot, and a 12-m.o.a. amber triangle.
What is Abacus ? Abacus is an instrument that was invented some 2500 years ago primarily in China, which later on spread through countries like Korea, Japan, Taiwan, Malaysia etc. It was used in the ancient times for calculating numbers through basic arithmetic system.
The abacus is moulded in three sections and has four main concave faces corresponding with the tapering volutes below and truncated by a short sqaure face on the diagonal. A board, tray, or table, divided into perforated compartments, for holding cups, bottles, or the like; a kind of cupboard, buffet, or sideboard.