Its probably one of the worst machines on the market!!! Steer well clear!
If the air is humid your crystals will get blocked and not work properly, same if any moisture gets in the system, plus repairs cost a small fortune!
I used to work for a microdermabrasion company that sold both beauty and medical grade machines and the difference was astounding.
Go for a crystal clear treatment then ask a few reps to come round from other companies and I promise you, you will feel how different they are.
Crystal clear feels like all it does it suck air! compare that to other machines that you really feel like a good exfoliation has took place.
You need to be able to control both crystal and air so you can alternate the both for clients more sensitive etc.
Also it helps if all the wiring is outside the machine as the tubes wear away (depending on machine its best to change them every 50 treatments).
Also are the heads a) disposable or b) sterilisable.
And no you cant do this treatment unless your qualified. You can cause all kinds of problems with microdermabrasion machines such as bruising, scarring and hyper pigmentation etc.
In the right hands the right machine can give fantastic results not just on the face but also on the body (back, bum, thighs or belly are popular) hands and feet!
kate