Asus Zenfone 3s Max ZC521TL official Pictures. Asus Zenfone 3s Max ZC521TL is a Smartphone of asus. The Asus Zenfone 3s Max ZC521TL Android Smartphone. Announced Jan 2017. Features 5.2″ Display, MT6750 Chipset, 13 MP Primary Camera, 8 MP Front Camera, 5000 MAh Battery, 32 GB Storage, 3 GB RAM. Asus Zenfone 3s Max ZC521TL price starts.