https://www.asus.com/Phone/ZenFone-5-ZE620KL/Tech-Specs/

A version
FDD-LTE (Bands 1, 2, 3, 5, 7, 8, 18, 19, 20, 26, 28, 32)
TD-LTE (Bands 34, 38, 39, 40, 41)
WCDMA (Bands 1, 2, 3, 5, 6, 8, 19)
EDGE/GPRS/GSM (850, 900, 1800, 1900MHz)

B version
FDD-LTE (Bands 1, 2, 3, 5, 7, 8, 18, 19, 28)
TD-LTE (Bands 38, 39, 41)
WCDMA (Bands 1, 2, 3, 5, 6, 8, 19)
EDGE/GPRS/GSM (850, 900, 1800, 1900MHz)

C version
FDD-LTE (Bands 1, 3, 5, 7, 8, 20)
TD-LTE (Band 40)
WCDMA (Bands 1, 5, 8)
EDGE/GPRS/GSM (850, 900, 1800, 1900MHz)

https://www.asus.com/tw/Phone/ZenFone-5-ZE620KL/Tech-Specs/
台湾のサイト見ると
B version = TW-2CA with NFC version
WWはA versionかC versionか…