STRICT COMPATIBILITY - ONLY FIT for ResMed Mirage FX: Made of high quality plastic material, firm, eco friendly and practical,wear‑resistant. Replacement Elbow outside diameter is 0.76 inches, Replacement Elbow inside diameter is 0.64 inches, Please check your MASK for compatibility! Fits ONLY ResMed Mirage FX: Regular changing the elbow Keep your nasal guard with good performance, your ventilator nasal and hose cleaner after regular replacement ONLY for ResMed Mirage FX: It is well made simple and reasonable,light weight, and small in size. Easy to connect and use with good performance DETACHABLE DESIGN: It has an elbow shape that can guide the hose to where it is needed so that it won t get in the way. Detachable, easy to clean, After regular replacement, the nasal mask and hose of your ventilator will be cleaner EASY TO CARRY:Nasal guard an important and practical accessory for breathing machine. Light weight, small size, easy to store and carry ONLY for ResMed Mirage FX Replacement Elbow/Swivel for ResMed Mirage FX Not Fit ResMed Quattro Air Not Fit Resmed Airfit N30i Not Fit ResMed Quattro FX Not Fit ResMed Mirage Quattro Not Fit Resmed Airfit N20 Not FIt Resmed AirSense10 Not FIt Resmed AirCurve10 Not FIt Resmed AirFit F20/AirFit F30 Not FIt Resmed AirFit F10/Quattro Air