Ideal for wheel and hub bearings up to 100mm ID. ABS plastic cones with threaded hollow steel central rod. Evenly injects fresh grease into open roller and tapered bearings. Quick and clean operation.
Yes you can pack them by hand which is messy and you can't be sure you pack them evenly, or buy one of these for a pittance. Don't forget, these bearings often only get lubricated once in their life so do it right.