1979 Ibanez TS-808 Tubescreamer 'narrow box'
The mother of all overdrive pedals. This TS-808 has small square metal on/off touch-button. There were some TS-808s made in the 1979 period, mostly for other than USA markets, like this oen, that came in a narrower box. These have a bottom plate that unscrews to change the battery like an MXR pedal, no plastic battery cover. This narrow TS-808 had a different circuit. It uses two 1458 chips which are the 1st version of the low-tech dual op-amp. Also the LEVEL knob on these is labeled BALANCE and the external 9V power jack is on the side next to the input jack.
This is the tube screamer you want!