ONE/SIZE Secure The Sweat Waterproof Mattifying Primer is a high-performance, sweat-proof, and waterproof primer designed to lock in makeup for up to 12 hours. It controls oil and shine while minimizing pores using bamboo marrow powder and botanical extracts. The lightweight, aluminum-free formula leaves a matte finish.

Warm a dime-sized amount of the primer in your hands.
Pat and press onto the skin rather than rubbing it in.
Allow it to set for 1 minute before applying makeup.