For your consideration is this interesting and perfectly functional Central States Manufacturing Company Speedo mechanical jar opener.
This cast iron kitchen tool features a jaw that adjusts to about 4″, plenty large enough for most jars that may be encountered in the days of ole or now. The sides are nicely marked with ‘Speedo Jar Opener Made in USA Pats Pend.’ on one side and ‘Central States MFG Co St Louis Mo’.
This is in good cosmetic and functional condition.
Please see the photos for more detail.