Hello Taylor,

Thank you for your question regarding buffing wheel sizes in the kits and what type of grinder to use.
All the buffing kits on our webpage state in the product description what comes in the kit including buffing wheel diameters.
Our professional polisher 21 piece kit part # BUFF KIT 21 will definitely get you started with your polishing needs. We do not include a grinder in it. Grinders tend to be a personal choice as to what a user prefers in terms of brand. Whether you are a professional, a do it yourselfer and/or budget can also influence what grinder you purchase.
We recommend a variable speed name brand machine, 7”/9”, 5/8” -11 thread arbor, 0 - 3500 rpm for the average user. DeWalt or Makita are good examples. Bauer, which you can find at Harbor freight tools is a decent machine as well for the budget minded.
Some professionals will use a 6,000 rpm grinder for the cutting step. We do not recommend this machine for the inexperienced or average user because if you’re not experienced with this type of machine due to its torque and heaviness in operating it, don’t use it until you become more experienced with a slower speed machine.
Another consideration is it exceeds our maximum rpm rating for our airway buffing wheels.
We will look at possibly including on our website a reference to using a variable speed machine.
Please contact us at sales@zephyrpro40.com if you need further assistance Taylor.