125khz-dat

https://w.electrodragon.com/w/Category:125KHz_RFID

card type use 45mm Dia. antenna use 97x97mm rectangular antenna
“nail” pin card 11 cm 14 cm
Dia. 2.5CM card 13 cm 20 cm
Dia. 3CM card 16 cm 24 cm
normal card 18 cm 25 cm
thick card 25 cm 41 cm

ref