TP-LINK TL-WN321G v4

Overview
subversions include v4.1

Below FreeBSD run dump is sourced from here and is presumed to be for this version (it's the only RT3070 derivative model).

 ugen0.5:  at usbus0 run0: <1.0> on usbus0 run0: MAC/BBP RT3070 (rev 0x0201), RF RT2020 (MIMO 1T1R), address d8:5d:4c:98:3b:7f run0: firmware RT2870 loaded

Links of Interest
54:E6:FC OUI