New dials are plastic and do not have model numbers printed on them. If you are replacing the dial on an older indicator, be sure to mark the model number on the body, just below the engraved serial number. This will make it easier to reorder spare parts in the future.

The damaged crystals are removed with a special tool which acts like a suction cup. You can improvise other methods but you're likely to cause damage. Often times the new crystal, which is slightly convex, can be snapped in by hand, but even here, we use special equipment to avoid damage to the indicator. It's best to leave this to someone with the right tools.

• Caution: Unlike many other test indicators, the bezel can not be removed without complete disassembly.

Movement disc (023042) is not suitable for parallel model 7021.

The orange hands are ridiculously expensive to buy so here is a word of warning: just about any cleaning product will wash away the orange paint, so don't try to clean them. Painting the hand with fluorescent red or orange enamel will work, but acrylic paints are not very good for this job.

The complete movement [51, 52] is inside the body, held in place by two flat head screws. If the crown gear is damaged, jewel is cracked, or the whole movement is hopelessly cruddy, this may be a quick, although costly, fix. Also, if the accuracy is off by just a bit and you are convinced that you have the correct contact point and the correct pivot installed, then replacing the movement may solve the problem.

It is possible to convert your inch model to a metric model (or vice versa). Those with graduations of .001" or .0005" can be converted to 0,01 mm. Those with .0001" or .00005" can be converted to 0,002 mm. This will require replacing the dial and the pivot. Complete disassembly is required.

Do not forget the anti-shock spring (023413). It prevents over-travel and should always be installed. Nothing holds it in place. It will fall out on its own if you open the cover or start to clean the movement.