15 inch digital photo frame Multi-language Built-in ... Frame option: Acrylic or wooden frame;4, Bottoms: 7 keysup/V+, down/V-, left, right, enter, exit, menu;5, Pictures Format: ... , alarm, calendar; 14, OTG, can connect to computer directly; 15, System: NTSC/PAL; 16, Mutual copy between memory and cards ... mass-production for your option;20, Bottoms: 7 keysup/V+, down/V-, left, right, enter, exit, menu;