The Humibuster 80-85mm Acoustic Guitar Feedback Buster And Humidifier comes from Ortega and is designed for most classical guitars.   Essentially the Humibuster 80-85mm Acoustic Guitar Feedback Buster And Humidifier is one product with two functions. Firstly, feedback problems on stage are eliminated thanks to BUSTER, which covers the entire sound hole. Secondly, after a gig where the stage lights have been drawing the life out of your guitar comes HUMI; the humidification system that maintains the relative humidity of your instrument. The main features of the Humibuster 80-85mm Acoustic Guitar Feedback Buster And Humidifier include: Humidity regulator and feedback buster 85mm diameter for most acoustic and classical guitars Easy To Use Great high quality design