The Urei LA-4 is a single channel compressor / limiter in half-rack format with very simple controls for input/threshold and output gain. Ratio control and meter function are selectable on these same two knobs. Attack and release times are not controllable.

The LA-4 used op-amp electronics and saw a couple very minor circuit revisions through its production and cosmetic changes. Black Panel and Silverface versions are largely interchangeable when properly serviced. The LA-4 is a very popular platform for modifications to expand its bandwidth and speed up the slew-rate of the audio electronics.

The rear panel features a high/low sensitivity switch and terminals for input and output connections. Later versions (post 1980) featured rear connections for stereo coupling.