Its handle is make of metal such as iron, and its upper end is a tough cylindrical brush with some protruding bristles. For different lengths and diameters have different sizes.
Method of use
1 Step : Moisten or fill with 1/2 volume of distilled water into tube. 2 Step : brush into the inside of the tube. Making the top stiff hairs stick to the bottom of the tube. 3.Step: put up and down the tube brush handle to clean the inner wall of the tube. And turn the tube brush at the same time. 4.Step: After cleaning, take out the tube brush. If the distilled water in the test tube neither gathers into water drops, nor flows down, clean up. Then pour the test tube onto the test tube rack.