TT 10 is equipped with a top-mounted, high-sensitivity GPS receiver and braided steel VHF antenna * Replaceable 1-inch collar strap with additional colors available * Rechargeable Li-ion batteries in Alpha 100 handheld and TT 10 dog device(TT 10 dog device: 24-48 hours depending on update rate) * Dog rescue mode switches TT 10 to a two minute update rate when the battery is less than 25% - extending battery life