All those Kahr models are hard to figure out.
Kahrs come in small, medium and large, (M, K or T).
Kahrs are metal or polymer framed.
Calibers are 9mm, .40 or .45, sorry no metal .45
T9 and TP9; Large metalframe, large poly frame
K9 and P9; medium metal frame and medium polymer frame
( I don't care for the small MK or PM sized Kahrs)
They also make an economy version of the polymerframes sm and med. called the "C" series, ( C for cheaper I guess