The octave pedal with moooore. One octave up, two down, plus a clever option to just double the lowest note you're playing. There's also a switch for guitar/bass to adjust the tracking appropriately. Add some chonk to your honk.

Model: Boss OC-5 Octave
Made: Taiwan; October, 2025
Serial: H9R2159
Type: octaver
Power Input: standard 9v DC centre-negative (supply not included)
Accessories: none

Condition notes: used, no major marks. Tested and fully functional.
Overall: excellent condition (9/10)