In my opinion, this is a must. If one is spending a premium amount for a fine delicate instrument (Moroso Tire gauge)then it makes sense in my book to protect that investment by purchasing a rubber cover. In case of an accidental knock, which can easily happen, you'll be happy that for a few dollars, your instrument in most cases, depending on the severity of the knock,will still function-plus it is easy to install.
Great idea:
I think the gauges should come with these already. Don't follow the installation directions, just lube it with some soapy water; there's enough "give" in the rubber to work it up over the hose and onto the gauge without disassembling.
You'll wish you bought one:
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... more info
Quality cover:
Gauge seems very beefy and made of quality material. It fits well. It should last a long time.