With the large, transparent and impact resistant grease cup, this unit is capable of repacking grease into 50 or more bearings, before needing to be refilled. You can fill the grease cup via bulk filling, or via the grease nipple on the bearing shaft retainer. The original method of packaging grease into a bearing is extremely messy and wastes a lot of grease too, however the Kincrome Professional Bearing Packer has solved this problem! The unit is extremely easy to operate, simply remove the plunger cone and fit the bearing over the bearing retainer shaft. Reinstall the plunger cone and press down with force or use a bench vice to push the fresh grease through your bearing while also removing the old grease.... it's that simple!