These handy 20 ml and 30 ml capacity metal tubes are designed for those who wish to make up and retain your own personal concentrations of adhesives, pigments or other compounds. The tubes are open on the bottom and easily rolled closed after they have been filled. The 20 ml tubes measure 3/4 x 4-1/4″ and have a fine plastic nozzle sealed with a plastic cap which you puncture with a pin or other sharp object. The 30 ml tubes measure 7/8 x 4-7/8″ and have a semi fine metal nozzle with a plastic cap. Replace the screw-on cap after each use. They are sold in boxes of ten tubes.