The brush is made of soft black fibres that taper to a dome shape. With the classic Mac hand made black wooden handle & nickel plated brass ferrule.The 224 works a dream for blending out eyeshadows. With more pressure added to the ferrule the wider the fibres spread giving a wide soft blend. Also with a light hand it can be used for a more precise controlled application. Although for smaller eyes this may not be the best brush as it is quite broad.If blending has ever been a problem for you the 224 will certainly help you out, it practically does the blending for you. Not only is the 224 amazing for blending eyeshadow, it also works well for the application and blending of concealer.
My one and only down point would have to the fibres shedding. Not even particularly when washing the brush does it lose fibres but just through daily use (I must add it washes & dries beautifully back into shape). I use the 224 brush everyday & roughly around every other use I will lose a few bristles. With that being said I don't notice any loss in density of the brush when the fibres fall out. All but one mac brush I own shed, so this really isn't a surprise to me or many other mac fans. Oh and the price £22.50 is pretty hefty, but I do have to admit it's worth every penny & I would repurchase.
If you don't have or don't want to spend £22.50 on a blending brush, the closest cheaper alternative I have come across is the Crown Brush C433 pro blending fluff brush. The main difference is this brush has white goat hair & is slightly more narrow so it doesn't achieve the exact same effect, but the idea of the brush is similar.
Whats your go to blending brush?