OTC Owatonna Tool Company. They manufacture specialty service tools, mostly suspension and driveline tools, but also A/C and electrical repair tools, too. Many car parts stores carry their tools, Napa is a good place to check. If you have a local repair shop or car dealer nearby, you might see when their tool dealer (Snap-On, Mac, Matco) comes around. Sometimes those dealers also sell OTC as a lower cost alternative or line expansion (for tools they don't manufacture themselves), if you don't have a parts store that carries OTC.
