This Wilson Equitron fixture looks like it has never been used and is in excellent condition with original wooden storage box. The box does have some wear but has a nice patina.  

The Equitron fixture is recommended for the end quench test for hardenability of steel generally referred to as the Jominy End Quench Test. The Equitron fixture, which is easily clamped to a Wilson hardness tester elevating screw, supports the specimen and provides means for accurately positioning the sample for successive Rockwell hardness testing at 1/16" intervals.
An indexing wheel, located at either end of the fixture, accurately spaces the indentations by moving the specimen 1/16" with each revolution. A ball click mechanism indicates each 1/16" space. Tests may be made up to 2-1/2" from the quenched end of the specimen. A scale is provided to indicate the positions at which the test is being made and permits testing at greater intervals than 1/16" if desired. The screw for moving the specimen operates in oil-less bearings.