The Breas 3 size headgear has slightly different design compared with the One Size headgear. It is a little wider on the top of the head with
slightly more air circulation and the two side straps are non-adjustable.
If you finds it difficult to get a near to perfect fit with the One Size headgear then the 3 size headgear may be a better solution.
 

Thanks to the flexible strings the Headgear is easy to adjust for a perfect fit. The 3 Size Headgear fits all Breas iMask and the IQ® mask from SleepNet. Together with the iMask, this solution offers a very simple and quick procedure to fit or remove the mask.