Suitable for packing bearings with an even spread of grease. Works on most tapered roller bearings fitted on cars, boats, trailers, etc. Clean and quick way to pack new or old bearings with grease, while expelling old grease. Lightweight and handy, with less waste than conventional grease packers, while being less messy too. No air line or grease gun required. Transparent, impact resistant cup allows grease level check.