The Napalm Compresa is based on a vintage MXR Dynacomp (with some Napalm tweaks :-)
Audio Connections
In, & Out : Unbalanced 1/4” Jack
Power
9V DC : Socket (2.1mm ‘Boss Style’), or internal battery (PP3 ‘square’ battery)
Footswitches
Bypass : Selects either Bypass or Compresa (indicated via LED)
Controls
Volume Control : Controls the volume
Threshold Control : Controls the threshold