Please check your face size before purchasing an inglet von singlet mask. The top of the nose bridge should sit at the top portion of your nose (about 2cm below the level of where your eyebrows start), and the bottom of the mask should "cup" around your chin. I have a small head and face & prefer a more snug fit to my mask - so you can see the contours of my face (I'm 175cm tall and 57kg, so I choose to wear a small size). If you like your mask a bit roomier, choose the next size up. The ears are adjustable, so both a medium and small would fit me.