This is actually a pretty cool invention. I think that this would be super helpful for always having the right size brush for every job. I know how annoying it is when you you’re painting a room in a house and you don’t have the right brush to get in every nook and corner. Been there before! That is why this is such a great product design though. The synthetic hairs are attached to a stainless steel ferrule that mounts onto a spring steel handle. I like this because rather than buying 7 different paint brushes, you can buy one adjustable brush that I know would work really well. Awesome product! Super cool design.