50-150ml is the main capacity for face wash / facial cleanser tube,diameter 35/40/45mm,round or oval shape tube.Most clients choose flip top cap for face wash tube,because of it's easy to get face cleanser with flip top just need to lift up the cap then squeeze the tube to get right amount of cleanser instead of screw off the cap.Of course other caps like screw on cap/acrylic cap/airless pump/bamboo cap also availabel if needed.For flip top cap,we have orirnted and non-oriented,the difference is orirnted caps will face the same direction when screwd on while non-orirnted caps may face to any direction.