This article provides you with relevant information to compare EDM 930 and EDM 900 aircraft engine data monitoring systems manufactured by J.P. Instruments. https://www.jpinstruments.com/shop/edm-930-primary/

As you will see, while appearing to have similar specs, the EDM 930 is a far more advanced product over the EDM 900.

EDM 900
(From $3,695.00 to $4,965.00)

Features:

Aircraft Engine Monitoring
Aircraft Manifold Pressure
Aircraft Engine Percent of Horse Power
Aircraft Engine Exhaust Gas Temp.
Aircraft Engine Cylinder Head Temp.
Aircraft Engine Oil ... Read more »