1987 Guyatone Japan PS-035 L-VI Limiter Compressor Pro

In the late 80's, Guyatone upgraded it's pedals with the Pro series. These were a similar build style to the previous series released in the 1980's, however had enhanced build quality and were aimed at professional/studio musicians. 

The PS-035 Limiter/Compressor provides studio-quality compression with the addition of an inbuilt filter circuit that acts as a tone control.