we use these primarily but have used others including estimote since 2013... https://www.gimbal.com/gimbal-proximity-beacons https://www.gimbal.com/gimbal-prox

we use these primarily but have used others including estimote since 2013... https://www.gimbal.com/gimbal-proximity-beacons https://www.gimbal.com/gimbal-proximity-beacons less than 5 dollars each for series 10 and a security model that folks should seriously look into IMO...or u can use iBeacon configuration. Originally by Qualcomm so u know the hardware is solid.