?android and ios?: Please prepare Nano SIM card which supports 2G GPRS GSM and GPRS function,you can search on Internet or scan QR code: e-Tracing. Double Mode Design: Mode one, standby 7-8 hours, the tracker will generally update pet dog`s location within 1 minute by standard model; mode two, standby 2-3 days, the tracker will generally update pet dog`s location within 30 minute by default model . Family Number: Not only use fitness tracker for small pets,nbsp; but also put the guardian's cell phone number to keep in touch thru best pet tracker, it can set 7 family numbers totally, wireless smart pet tracker will trace pet step tracker. Electric Fence: Setting an area around locator, alarming immediately when the pet getting in or out the area. Put a electric fence name and set in or out the fence alarm for live pet tracker. Callback Function: Setting the callback number. And cllck the "sure" button. The best location wireless smart GPS tracker will automatically call to the phone number you set. Historical Track: Record the pet tracking within 3 months. You can check your pet's walk's route easily. Firewall Setting: Factory setting is closed, open this function, to help the device avoiding crank call. Item Name: Pet Tracker; Mian Material: ABS+PVC, Electronic Parts; Item Body Size: 65.5 x 37 x 18.3MM / 2.58" x 1.46" x 0.72"(L * W * H);nbsp; Packaging Size: 92 x 92 x 62MM / 3.62" x 3.62"nbsp; x 2.44"(L * W * H); GSM: MTK2503D; GPS: GPRS+BDS+LBS; GPS Sensitivity Degree: (-165DB); GPS Precision: 5-15M / 16.4-49.2Ft; LBS Precision: 100-1000M / 328.1-3281.8Ft; Default Mode: Update 1 time per 30 minutes, standby 2-3 days; Standard Mode: Update 1 time per 1 minute, standby 7-8 hours; Working Temperature: 20C to +55C; Battery: Polymer 500 mA; Connector Type: USB connector; GSM Frequency: 850/900/1800/1900MHz; Weight: 186g / 6.56oz; Package Include: 1 x Pet Tracker, 1 x USB Cable, 1 x Pet Belt, 1 x Chinese-English Manual.