I’m stocking up because they’re $29 off for 4 from Amazon! I keep one in checked luggage and in my purse (in case it’s lost or stolen). When my suitcase didn’t make it to its destination , being able to see where it actually was and track it was enormous peace of mind. You can also add it to your keys or a dog collar! LTKHome LTKOver40 LTKSaleAlert