Using this 6 oz round plastic liquid pump dispenser is a breeze. First, twist off the cap. Then, fill the dispenser with your preferred liquid like acetone for nail services or makeup remover. To dispense the liquid, simply press down on the pump. As for maintenance, it's a good idea to clean the dispenser regularly. You can do this by emptying it, then rinsing it with warm water and a bit of mild soap. Make sure to dry it thoroughly before refilling. Regarding the cap, remember that the color you receive depends on what's available. And always keep it tightly closed when not in use to prevent leaks and evaporation.