Best Buy offers the TrackR Bravo Tracking Device Set in Silver/Black/Blue/Rose Gold, model no. TB0014COLORS, for $69.99 with free shipping. That's $30 under the lowest total price we could find for four devices separately elsewhere. (For further comparison, we saw one device for $20 on Prime Day.) These coin-sized devices feature 2-way separation alerts to remind you not to leave items behind.