Here is what Mike says…

‘The Skull - One Knob Fuzz.

Fuzz / Distortion pedal, big sound, small package. 

Featuring single MPSA13 transistor & BAT41 diode pairing, true-bypass switching and red LED.

Single volume knob.

Runs on external 9v pedal power supply (not included) centre negative, sleeve positive.

Skull enamel artwork.’