For the door type common to Saginaw's 1990s-2000s builds, we stock torsion springs sized to standard 7-foot and 8-foot sectional doors, steel rollers (sealed bearing, not the open bushings that wear out fast in heat), galvanized lift cables, and nylon idler bearings for the torsion bar. We also carry photo-eye sensor pairs and standard drive belts/chains for openers from that same era.
What we don't stock on the truck: proprietary circuit boards for a handful of discontinued opener models. If your opener is one of those, we'll tell you on the spot rather than make you wait on-site while we guess - sometimes it's a same-day part, sometimes it's a lead time of a few days, and sometimes replacing the opener outright is simpler than waiting on a board nobody makes anymore.