Easy install, good product. [I chose EI because of my] experience with [the] product.
- Customer
Dave S. from Missouri
- Aircraft
Beechcraft Bonanza Model 35
- EI Instrument
8am–4:30pm PST M–F
Sorry, We’re Closed
Our TR-1 provides exceptional performance, reliability and features. If you need to replace or overhaul an old failing instrument, consider buying one of our TR-1s from a company which has been designing quality aircraft instrumentation for over 40 years. Purchasing our TR-1 is substantially less expensive than overhauling or replacing your old needle gauge. We’re able to make this offer with a money-back guarantee because we’re confident you’ll love the performance, reliability and features these instruments offer.
| Amps | AOA | Bleed Air Temp | Cabin Pressure |
| Diff Air Pressure | EGT | EPR | Fuel Flow* |
| Fuel Level | Fuel Pressure | Hyd | ITT* |
| NG/N1* | NP/N2* | O2 Pressure | OAT |
| Oil Pressure | Oil Temp | TAT | TGT |
| Torque* | TOT | Volts | And More! |
* See Product Page
We offer two package options for our TR-1 instruments: Standard and Premium. The Standard TR-1 package is designed to meet the price point for customers wanting rugged and reliable replacement instruments at a great price. The Premium TR-1 package is targeted for customers that need to minimize AOG time.
Bluetooth Field Calibration Device [FCD-TR-1] (add $600)

Dimensions
2″ standard round, 4.23″ long
Weight
0.3 Pounds (Instrument Only)
Power Requirements
6 to 55 Volts
Typical: 0.075 amps @ 28 Volts
Dimming
Auto (electric eye) and Manual
Environmental
DO-160G
Internal Storage
1,000 hours, RS232 port (premium only)
Certifications
FAA TSO’d -C43c, -C44c, -C45b, -C47a, -49b, -C55a

Easy install, good product. [I chose EI because of my] experience with [the] product.
The display is large and clear. The functions are simple and easy to use. Great purchase decision.
Easy installation.
The OPT-1 is more readable than the factory Cessna oil pressure/temp gauges.
We have other EI products currently and have always been satisfied.
People [at EI] were great to work with.
Staff appears to be very helpful when assistance is needed in verifying information. Heard good things about it [EI] from personal known aircraft owners.
The equipment is fantastic, very intuitive, and easy to use.
Phone service for ordering was quick and easy. Shipping was quick.
[I chose EI because of its] reputation [and the] quality and appearance of the instrument.
Every person was willing to help me when I needed and the whole purchasing process was smooth. [And, E.I.] was recommended by my mechanic.
Easy installation, lightweight solution. It looks good and is easy to use. [I chose E.I. because] I needed to replace my old Hobbs meter. This provided more functionality, allowing me to remove my old digital timer, and EI programmed it to my current airframe time.