About Product M: Synthetic fiber face powder brush, a large brush with full and dense hair for applying loose or pressed powder on face or body. Size: whole length 142 mm; hair length 49 mm; hair width 37 mm. F: Synthetic fiber foundation brush, a flat top brush with slightly rounded edge, for buffing creams or liquids. Size: whole length 111 mm; hair length 17 mm; hair width 35 mm. L: Synthetic fiber face powder brush, a rounded brush with full and dense hair, for applying pressed powder on face. Size: whole length 122 mm; hair length 31 mm; hair width 38 mm. Please allow about 1 mm error due to manual measurement. How to Identify Natural Hair and Synthetic Hair Method 1: Burn it, if it smells like we burn human hair, then it is natural hair; if it smells like we burn plastic, then it is synthetic hair. Method 2: Wash it, after dry, the synthetic hair will be almost the same as before, but the natural hair will get fluffy if you don't shape it. Tips: If you don't want the natural hair to be too fluffy, please wrap it with facial tissue after wash, and also for big brush, you could use the brush guard net that we send to shape it. How to Clean Clean your brush before using it the first time. For daily cleaning routine, consider using a mild brush cleaner. Use the following method to keep your brush clean. We recommend weekly cleaning. 1. Use the warm running water, (being careful not to fully immerse the base of the bristles) to get rid of as much product as possible. Try using your fingers to get rid of any bits lodged toward the base of the brush head. 2. Place a pea-sized drop of brush cleanser(or any mild cleanser like baby shampoo) in the palm of your hand. 3. Swirl the bristles in the cleanser in a circular motion until the brush is fully lathered. 4. Rinse the bristles, squeezing from the base to the tips to remove excess water. 5. Repeat until the water runs clear and all makeup is removed from the brush. 6. Reshape the bristles to their original form and then use a lint-free cloth to dry each of the brushes, or you can let them air dry and place them on a cloth. You can also gently brush bristles on paper towel to remove buildup. Or you can use the brush protective net to keep the brush shape when the brush is almost dry. Tip: Wash brushes at night so they are dry and ready for use in the morning.