The C7 rifle, standard primary arm of the Canadian Forces, is an AR-10 variant derived from the American M16A2, and produced by Diemaco / Colt Canada. It has two primary variants - the fixed-stock C7A1, and the collapsible-stock C7A2, which also features an integrated TriRail system near the front sight for mounting of various rifle accessories. These come standard with the C79 sight system, produced by ELCAN - a Canadian subsidiary of Raytheon - which provides 3.4x magnification with a simple tritium-tipped post and horizontal milbars for ease of ranging. (The C79 sight was originally developed for the C9 LMG, which is a variant on the American M249 Squad Assault Weapon.)
The C8 rifle may also be considered a C7 derivative, though it traces its origins more closely to the M4A1, and will be discussed in greater detail in its own writeup.