Two microdroplet diffusers by Aera. One is model AQ30 and the other is model AQ31. The only difference being that the AQ31 model is a smart model that works with an app. I am including two unused diffuser capsules and two used capsules that still have product in them. Each capsule full price is $60 and you now have $120 free product plus the two partially used capsules. Each capsule lasts an average of 500 hrs. The scents that are new are Revive Morning and Forest Therapy. Two used capsules are Sweet Rhubarb and Beach House.