I have try out other hairsystem from many different companies and have notice that each company seems to run there own density percentage chart. I ordered a system fron toplace that was 68% which was good for me ,I'm 40, but when i went to another company and asked for 68% it was way to light and was told that i would have to order 90% to egual Toplace 68%. It get very confusing because to get a light to medium from Toplace you order 65% but to get light to medium from others it is 90%. I also aked about the density scale on Coolpiece and was told the there 90% is egual to Toplace 65% and there was no such thing as 68% that the scale only runs in 5% increments so it is either 60-65-70% no 68% or 63% an so on. I also check with HD and they are telling young guys under 30 to order to order 70%. I am in my 40s and toplace 68% works for me and HD wearers mentions 70% for guys under 30 whick makes no sence if I wear 68% and i am in my 40s why would HD wearers tell guys in there 30 to just have have 2% more t Why does everyone have a diffent density scale ?