From what I studied in my Esthetics program and done personal research, these set features bamboo handles and hard wood handles is the most durable type. The bristles are made from Taklon which is a synthetic fiber so it makes it more hygienic. Natural hair traps dead skin cells, bacteria, chemical and cleaning them may not remove all those particles so using a disinfectant with regular cleaning will prevent skin irritation. Taklon lacks those irregularities so it's easier to clean properly and decreases skin irritation. Synthetic and natural hair brushes has their cons and pros so it depends how you use them. These set is allergy free, cruelty free, and of course eco-friendly. Also, this may be less expensive than high end brands because natural-hair brushes are said to be softer but diameter variation affects the stiffness or softness of the brush. Synthetic brushes can be soft to and last longer if you take care of them.