What is the Difference between the black dryer and the purple?

I was considering purchasing this Signature Series (SS) model or the Black Gold Professional (Pro), so I asked Helen of Troy customer service for the differences (as of this writing, their website was of no help). They said the barrel of the Pro model is coated with 24K gold for heat distribution (it's painted black for looks), while the barrel of the SS is ceramic. They commented that 24K gold is very durable and added that ceramic is also durable but lightweight (not sure if they were saying that the SS is lighter weight than the Pro). The Pro's cord is longer. Otherwise, both units function the same. They said the Pro gets a bit hotter than the SS and therefore recommended the SS for my hair type (somewhat fine but not overly, lots of it, wavy/curly). I've since tried both models and find the company's statements to be true. Both get very hot, so you'll want to take care with either model to avoid frying your hair if your hair is fine at all, but the Pro does seem very slightly hotter than the SS. I can tolerate the sound of the SS better than the Pro, but that simply could be variations in the specific units I tried. I couldn't tell any difference in the weight, but I didn't have them side by side. They do seem to be substantially the same except for the differences I've stated. Because the company recommended the SS to me for my hair type plus it's lower in price, that's the one I'm going with, but the Pro would have worked fine for me, too. They both did a good blowout in half the time it takes me with a round brush and dryer. I'm not sure the heat level of each makes that much difference up at these temperatures--they both get really hot. Both have a 7 year warranty.

What is the wattage of this dryer?

Hi, Thank you for your question. The Hot Tools Professional Detachable One Step Volumizer and Hair Dryer is 1100 watts. Thank you.

Is this brush designed for short to medium hair that is 4 to 5 inches and layered?

This smaller barrel works well for my hair that is about 5-6". It took about 5 uses to get the knack of it. It dries quickly but does not give quite the volume and lift at the roots that I'd hoped for, so still use a velcro roller at the end. I was going to return it but I do like how fast and easy it is to dry. It is better than the Revlon one I tried.