Optimum for concealed carry because of the flattened profile. Plus, the medium high ride design positions firearms for a smooth draw. 3 Slot design on all configurations allows for crossdraq, dual position or strong side carry.

Size Guide
Size: 0 - 2-3" Barrel Small/Medium Double Action Revolver
Size 1 - 3-4" Barrel Medium Automatic
Size 2 - 4" Barrel Medium  Revolvers
Size 5 - 4 1/2"-5" Barrel Large Automatic (Open End)
Size 12 - Glock 26,27,33 and other subcompact 9mm/.40cal autos 
Size 15 - 3 3/4"-4 1/2" Barrel Large Automatic (open end)
Size 16 - 3 1/4"-3 3/4" Barrel Medium & Large Automatics
Size 19 - Colt Gov't large autos, browning, hi power
Size 30 - HK USP 9mm, .40, .45, USP Compact
Size 36 - 2" Small Frame 5-Shot Revolvers