I'll state the obvious - it's too expensive and should have been included with the Moroso 89560 tire pressure gauge. However, if you don't buy it you'll wish you would have because the gauges have a light/cheap feeling to them (not the whole gauge - just the head). I topped off 8 tires on my two cars this evening, and for every tire I put the gauge down on the ground twice (to check before and after). If I didn't have this big rubber cover surrounding my gauge it would have been scratched up by now. The cover sticks out over the edge of the gauge head and protects your investment very well.
Also, I listened to a previous reviewer and decided not to disassemble the gauge to put the rubber cover on. It was flexible enough to stretch over all parts of the gauge without causing any damage to the gauge or the cover, and no lubrication was needed.
Quality cover
Gauge seems very beefy and made of quality material. It fits well. It should last a long time.
Guage cover
This is essential I think for the air gauge, but should be included with the gauge.
Functional guage protector.
It appears as though this cover will supply adequate protection. It was not difficult to install.
Better looks and grip
The guage has a cheap look and feel without the cover, I agree it should come with the gauge, but since it does not the best thing to do it purchase it. Each time you grab the gauge you will appreciate the cover and it does help protect it as well.