Latest 3G GPS tracker: Works worldwide. GPS + LBS + Wifi Positioning: Shows the location pinpointed in real time or periodically. You can take it easy even when your dog runs out of your sight. Sensor Lights: When it gets dark, the tracker device opens the LED flash automatically. Water Resistant: Fine in rain and showers but not suitable for soaking in the water or wearing when swimming. Suitable for Medium and Large dogs. Note: SIM Card not included. This will have to be purchased from your Cell Phone provider.