| Roller / grinding heads with different coarseness (fine / coarse) | You can use coarse for thick callus, fine for maintenance. Helps avoid over-scrubbing. |
| Two (or more) speed settings | More control so you don’t damage skin. Start low. |
| Rechargeable / USB charging | Saves cost of batteries, more convenience, especially with power fluctuations. |
| Waterproof or water-resistant design | Can be used in wet conditions / easy to clean. Reduces risk to device. |
| Built-in safety features (pressure sensors, auto-stop, etc.) | To prevent skin injury. |
| Vacuum or shavings catcher (optional) | Less mess. |
| Good warranty or return policy | Especially when buying from local stores or online with shipping. |
