... order 3. GPRS communication mode Customized Portable Wireless GPRS SMS Printers Hardware Instruction Pull to open the cover, and ... M, N, O, 67 key:p, q, r, s, P, Q, R, S, 78 key:t, u, v, T, U, V, ... For better GPRS data transmission, suggest prohibiting all voice and SMS functions in this SIM card)2. Install GSM antenna3. ... Paper Out!!!Press Print Key Customized Portable Wireless GPRS SMS Printers