The E39 Buff and Blend features a shorter, round dense brush head that blends colors softly, but with precision onto the lid for a diffused effect. SigmaTech Fibers - Sigma Beauty's exclusive selection of high performance synthetic fibers engineered to outperform traditional animal hair. Features technologically advanced filaments with specialized tips developed to hold and deliver cream and powder products without any absorption into the bristles. Built to last, SigmaTech fibers are antibacterial, hypoallergenic, and will maintain its original shape and color even after multiple washes. What else you need to know: Ferrules - The patented 3-ring brush ferrule is made with high performance SigmaAlloy for durability and strength. Patent No. D718060. Handles - Each brush handle is made from a lightweight, sustainable source of wood which receives 8 coats of paint, making them scratch resistant and guaranteed to last.