Durable and Sharp: Made of high quality material, solid brass shaft and diamond wheel are super wearable, a wheel can be used for years depending on the frequency of use. This provides the best paw trimming and painless smoothing of your dog's nails with exceptional durability How to Replace: Just take out old grinding wheel from the slot and push in the new one Eco-friendly: Use the replacements to increase the lifetime of the nail grinder, reducing the waste of money and saving energy Washable: Primens dog nail grinder head has been made in a way that it can easily be washed. Keep in mind that you will have to detach the head from the grinder before you attempt to wash it