My friend Sarah found this cool old-time hand gripper in an antique shop somewhere in Michigan and snapped it up for a few bucks. – What a steal!
There's no date on this gripper but I’ve seen the design before in a lot of old magazines going back at least as far as the 1920's. The one above is in mint condition (including the box) and still a pretty good challenge with all six springs. The Whitely Giant Power Grip was made by Moosehead-Whitely, Inc., in Hackensack, New Jersey.