Retractable aluminium lip brush. (Synthetic bristles). Akoi Brand.
Perfect for applying your lipstick from a tin or to get the last bit from your lipstick tube.
I recommend when you first get your brush run your fingers through the bristles to loosen them up.
Take the lip off and then push it onto the bottom. This will push and hold the brush up. To retract the brush remove the lid from the bottom and the brush with retract down. If the bush doesn't automatically retract, just push the bump on the side down manually.
To Clean Your Brush:
Dip the head of the brush in oil (like coconut oil or olive oil) and then wipe on a rag or paper towel. Repeat till the brush is clean and there is no oil residue. (this works because lipsticks are oil soluble, not water soluble. If you want to use soap then I recommend liquid detergent and hot water, it will break down the oils in the lipstick.