optimize ascending performance with different fluid viscosities etc persons skilled in the art will understand that the bypass valve assembly described herein u2014 the assembly of the cage valve stem and clutch u2014 may be constructed in a variety of combinations of the above features and interchanged with other combinations to suit particular conditions of individual oil or gas wells for example the plunger and bypass valve assembly may be produced in several diameters for use in different size well tubing also different length plungers may be provided for example a shorter bypass plunger is better able to negotiate well tubing that have curves or elbows and because of its lower weight it places less stress on the bumper spring at the bottom in wells that are relatively dry a longer casing falls more easily through more fluid and provides a better sealing action this adaptability is yet another advantage of the present invention as is well known performance of a gas lift plunger may be reduced if the configuration of the plunger is not well matched to the conditions of a particular well one important component of the clutch assembly to be described herein is the elastomer tension band in this description the use of the singular form of the term u201c tension band u201d.