Your Mobal World SIMes with a UK phone number. Your phone number works wherever you are in the world so your friends, family and colleagues always dial the same number to reach you! Phone Specification. Bands. 2G/GSM: B2 (1900), B3 (1800), B5 (850), B8 (900) 3G/UMTS: B1 (2100), B2 (1900), B5 (850) Phone Body.