Whistle GO Explore is a pet Health + Location tracker - Pink Collar NOT included (just sowing that you can purchase a collar to attach the whistle to) Green light charged Red light charging Whistle GO Explore is a pet Health + Location tracker Whistle Go Explore 2.0 features GPS tracking in addition to health and activity monitoring. So, you always know where they are—and how to help them stay healthy and happy. Whistle GO Explore is a pet Health + Location tracker that has 2 attachment options - the hook & loop attachments that fit on flat collars up to 1 inch wide, or a Twist & GO collar with an integrated attachment. Serial number will always start with W04- (serial number on unit is W04-40B18C2) Has a micro-USB charging port (cord not included) Has a plain lug protruding from bottom for inserting into collar attachment or Twist & Go collars Knowing their exact location Waterproof up to 6 ft For dogs 25 lbs and up Connects to a smartphone Collar NOT included Smoke free home