This Kimble-Chase Mark-M disposable culture tube features a ceramic label permanently fused to the soda lime glass which may be easily written on with marker or pencil. Writing placed on the label is permanent, making these tubes ideal for use in cell washers and water baths eliminating smeared, illegible identification of test samples. The plain label is located 3/4in from the open end of the tube. The soda lime glass tube measures 18 x 150mm, has a sturdy, uniform bottom with consistent length. Material: Soda Lime Glass. Label Type: Plain. Dimensions: 18 x 150mm. Kimble-Chase #: M18.