The ASI3-400 is a 3-1/8 inch aircraft airspeed indicator designed for piston aircraft panels. It displays airspeed using a pitot-static system and is available with multi-unit markings (MPH / KPH / knots) depending on configuration.

This model is a modern electronic/mechanical hybrid instrument (MEMS-based in newer versions), and is intended mainly for experimental and light aircraft use rather than certified IFR panels.

It provides a wide range up to 400 units (depending on calibration scale) and is designed for clear readability across low and high airspeed regimes.

Key features include:

3-1/8” standard instrument panel size
Display range: 0–400 MPH / KPH / knots (variant dependent)
Pitot-static airspeed measurement system
Multi-unit scale (switchable or multi-marked depending on version)
Designed for experimental / light aircraft installations
Compact installation depth (~96 mm)
Electrical version requires 9–30 VDC power (on electronic variants) 
Lightweight instrument (~380 g class) 
Direct indication of indicated airspeed (IAS) from pitot pressure system
Used in general aviation panel upgrades and experimental builds