Abstract: In a marking pen, the body of the marking pen containing the cartridge is made air tight except for the opening on the distal end to receive the marker nib and a vent hole. The walls of the pen body are made flexible and the vent hole is provided through the flexible walls near the distal end so that the cavity containing the cartridge can be pressurized by squeezing the body between the thumb and index finger, with the index finger covering the vent hole. The pressuring of the cartridge cavity applies hydraulic pressure to the nib to flush the nib with ink or unclog it.

Abstract: A tube liquid dispenser includes a resilient tube, a filter positioned in the tube at one end, a flange of sealing material extending radially around the outer circumference of the tube, and an opposite end closed except for a dispensing opening of a size through which liquid passes only upon the application of pressure to the liquid.

Abstract: A freeze and thaw indicator is provided utilizing the expansion characteristics of water when it undergoes a change from the liquid state to the solid state. An ampul having one side made weaker than its opposite side is substantially filled with water. Indicator paper having ink printed on one side is situated adjacent to the ampul. The indicator paper and ampul are housed in a blister pack plastic container for protecting the ampul from breakage. When the temperature around the indicator reaches the freezing point of water, the ampul breaks. During a subsequent thawing, the water flows on to the indicator paper causing the ink which is printed on one side to wick up, thereby indicating that the freeze or thaw has taken place.