A mask for delivery of respiratory therapy to a patient may include one or more of the following improvements: rigidizer provided to headgear strap, locking clip/clip receptacle headgear connection, keyed headgear buckles, lotion dispenser on frame, rotatable prongs to adjust orientation, alignment indicators provided to prong, cushion and/or frame, chin flap with bellows arrangement, vent holes positioned away from gas entry port, and vent holes to direct washout gas at an angle.