Do you still have the box the brush came in? The directions are on the back of the box. If you don't have the box, here are the directions:
To open your brush, hold the part of the brush that says “Brush On Block” in one hand, and the part that says “Mineral Sunscreen SPF 30” in your other hand. Turn the “Mineral Sunscreen” part of the brush very slowly to the left about ¼ to ½”. The brush should naturally want to stop here, and you may hear a click. Your brush is now in the Open position. (If you twist too quickly, or too far, the powder cartridge will unscrew from the brush. This is how you can refill your brush later on.) Brush On Block is proud to be one of the few mineral powder sunscreens on the market that has an Open/Close mechanism on our brush. We have included this feature, because we know how frustrating it is to open the brush in your sports bag or handbag and find that much of the powder has ended up inside the cap, not the brush. The Open/Close mechanism keeps the powder inside the brush until you want it to come out.
Before you remove the cap, turn the brush upside down while it is in the Open position and give the brush a few firm taps on a flat surface. This will fill up the tube that runs from the powder to the bristles, so that you powder can flow smoothly. Then flip it back over, remove the cap and slide down the yellow sleeve over the bristles. Now you’re ready to apply!
When you’re done, pull the yellow slider back up over the bristles and reapply the cap. Then click the powder cartridge back to the right into the “Close” position.
