there are two types of this kind of tubes, one is with one ball, the another one i with three balls on the tube head part.  tube is sealed by screwing on cap tightly. if we screw off the cap, content in tube can be squeezed out. material of cap acrylic outer capppinner cap turning the ball on skin, content will flow out and apply on skin. easily use, and it brings massage effect to the skin. it&rsquos suitable for thin content, like antiperspirant deodorant, emulsion, serum, etc. source httpauberpackaging.comproduct70552.html