There is a lot of older farm and industrial equipment still running 6 volt systems. Tractor Supply Company (TSC) stores are across most of rural America and keep the type 1 case 6 volt on the shelf as a rule. The last time I bought one (which, I need to state was a few years ago) it came with the threaded caps. This is worth knowing as Sav-A-Battery filler caps of certain sizes/thread types will fit & were a (I know from experience) good thing to have as they warned of potential problems before the battery died the death.