What does gsm unlocked really mean: Unlocked devices are compatible with GSM carriers ONLY. I.E. Networks that Use SIM Cards for Service like AT&T and T-Mobile, as well as select prepaid GSM SIM cards (Cricket, H20, Straight Talk, Wal-Mart Family Mobile, NET10), Unlocked Devices will not work with CDMA Carriers, The kinds that don't use sim cards for service like Sprint, Verizon, Boost or Virgin.

Hardware specs: Battery Size is 3180mAh, removable Li-ion which on standby lasts up to 11 days as well as 19 hours of talk time, This device has 16GB eMMC 5.1/ 2GB LPDDR3 the software on this device is a proprietary version of Android 7.1.2 and this device weighs260 Grams. in the package you'll find a complimentary screwdriver to attach the back door of this device (be careful not to screw too tight as it will strip the screws rendering it not waterproof).

What Network and on what frequencies are supported by this device: The Sonim XP5s runs on the following Technologies GSM: 850/900/1800/1900MHz. UMTS: I/II/IV/V/VIII. LTE: B1/B2/B3/B4/B5/B7/B8/B12/B13/B14/B25/B26/B28/B30/B38/B41/B66

Does this device need a sim card: Yes it does Since this device is Unlocked it will work on any GSM Network with a MICRO size SIM Card The sim card does NOT come included and you will need to contact your Network Provider to acquire your complimentary Sim card (Free from most Carriers with activating of an account).

!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! Will not work on verizon or sprint !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!