There are a very wide variety of buffers used during nail services. They are available in different grit sizes: the lower the grit number the harsher the abrasive; the higher the number the softer the abrasive. They have many different constructions in what they are made of and how. Some are designed as single use, others can be washed and disinfected. Some have a rigid centre and others are made on a sponge centre.
