The original OD-850 released in the 1970s was not an overdrive, it was more or less based on the Big Muff circuit which itself is more distortion than a fuzz in many players' minds. So here we have a drive pedal of some sort or another.
The tones will get you all of those huge Big Muff style tones heard from bands such as The White Stripes, Smashing Pumpkins, Thin Lizzy and SOOOOOOO many more but where the Big Muffs are famously HUGE this is a tiny well-designed pedal from Ibanez so you know it'll stand up to being stomped on for years to come.