Minimum caliber for Limited division is 9mm, however, most competitors use .40 or .45.  Pistols are generally "double-stack" single action autos.  No limit on magazine capacity, however, magazines are limited to 140mm length, 170mm for single stack pistols.  Optical  or electronic sights are not allowed.  Compensators and/or barrel ports are not allowed.  Race-type holsters are allowed and there are no restrictions on position of holsters and magazine pouches.  Common brands used are:  STI, SV, Glock, Paraordnance, CZ, and Springfield.  This is the "stock-car" of practical shooting.