It would be handy to have a couple of pressure gauges in appropriate ranges for verifying that ones you are relying on are accurate and working. You will need some adapters to be able to plug these in various places. Get adapters to suit your requirements. The flow sight gauge that we got from John Ernst Co, was a 3/8" and the unit was too large for the amount of fuel flow, as the wheel would rarely spin from the low level of fuel running in the line. A 1/4" unit would have been more appropriate. The engine is a John Deere, 135 HP and the fuel flow is less than 1 gal per minute. If you have an inverter or you are using any of the "Class T" fuses, they are hard to get and you should be careful to carry spares in the appropriate sizes. Regards, Mike Capt. Mike Maurice Tualatin(Portland), Oregon.