Amazon with Momax Technology (HongKong) Ltd. has the MoMax Device Tracker Tag (multiple colors) for $19.99 - 50% off with coupon code 50KEQSPE [Exp 3/26] = $9.99 with free shipping on $35+ or with Prime. Other trackers are also 50% off with the same code.

Compatible with Apple's Find My network. Features a "Lost Mode" which will send a notification to your phone or device when your tagged item has been left behind.