s7-300 tc modules

Hello all,

I am replacing some old Siemens S5 modules (6ES5 646-8MA21) with S7-300 that measure thermocouples. I have been looking at modules 6ES7 331-7KF02-0AB0 and 6ES7 331-7PF11-0AB0 which both will work with TCs. I am leaning toward the 7KF02 and wanted to know what the difference is between the tow modules listed above or what advantages the 7PF11 has over the other.

Thanks, mrt19