CAPI VP312 Microphone Preamp W/Litz Output Transformer and Red Dot Opamp. It sounds just like my old API 3124+ mic pres. I built this about two years ago and it has become my favorite mic pre.It has the stepped input gain knob with a variable output knob. This listing is for a single VP312 with stepped gain. The other preamp modules and the lunchbox are not included.