Brush on Block is an innovative, revolutionary mineral sunscreen integrated into a brush, providing perfect sun protection. Main benefits Easy application, ideal for frequent use. Apply over makeup as a light powder. Ideal for people with sensitive skin. Suitable for oily skin.result Broad spectrum protection SPF 30. Non-irritating protection against harmful UVA and UVB rays. Translucent formula. Invisible coverage on all skin tones.How it works Brush on Block comes in an integrated refillable brush. It closes tightly so it wont leak into your purse or gym bag. When the mineral powder runs out, simply pop out the cartridge/refill and replace it with a new one.