A dual-ended brush developed, tested, and perfected by celebrity makeup artist Ariel to apply concealer. Brush Coverage: Buildable Bristle Type: Synthetic What Else You Need to Know: Using his expertise, Ariel created this versatile Morphe X Ariel A19 Signature Dual-Ended Concealer Brush. I can't live without this brush, he says. Being dual-ended, it gives me ultimate versatility to apply concealer in hard-to-reach areas and perfect my signature look.