This is a set screw lock collar. It is for a 0.75 or 3/4 inch shaft. They are steel and zinc coated. Perfect for keeping your shafts or bearings in place.
Shaft Collars (sometimes called lock collars) are easy to install; the collar provides an easy way to keep your shaft from sliding or your flanged bearing from coming out.
This is an Enclosed 4-wheel drive remote control robot kit. It uses four powerful wheelchair motors and the inside robot cavity has plenty of room for electronics.
900 MHz 3 dBi Rubber Duck Antenna - SMA Male Connector