BK Beauty Angie Hot & Flashy A506 Concealer Brush Hole No.: Borehole Log BLT 1A: Secondary Canals and Drains Rentang. For applying under eye concealer, you'll love this smaller kitten paw version of the BK 101 contoured foundation brush so much! Use it in a patting motion to apply under eye concealer. It blends out smoothly and seamlessly every time! It can also be used to apply concealer by the sides of the nose or to other areas of the face. Its also great for contouring! This is part of the softest, most luxurious brush set made specifically for mature skin.