This is a Brushless Cooling Fan measuring 60mm square and is powered by 12VDC.
These large Tiller Traction Lug wheels are 13" in diameter. They come as pair and have steel 5/8" diameter shafts and bearings.
Beacons are mounted on walls or ceilings to measure distance to other beacons and “hedgehog” using ultrasonic pulses. They communicate with router wirelessly in ISM band. Powered by LiPo battery or USB. Indoor Positioning System (IPS)