The diffuser has a useful ergonomic shape. However, the holes that allow air in it a little big. Therefore, they do not reduce the power of the blast as it would be desirable. However, the advantage is that it dries hair faster, but you need a quick hand to achieve the desired effect for volume and curls when used.
In several comments, I noticed that a number of people did not know how to use this accessory. For information, it is for hair that is desired to give volume. For this, we take off with the fingers and the pins of the diffuser hair at the root, in contact with the scalp or a few centimeters and it keeps the position for a few moments. The other use for curly hair, is to press the damp curls between fingers and slide them into the broadcaster by making a movement from bottom to top to give them the spring. In both cases, it pays to do it right then head alternately head to the ground.
It's very effective before styling!
Appraisal: I recommend it for the price / quality ratio
