[Blarg]

Never seen an adjustable one. I've seen all kinds of weird contraptions, though. This regular old familiar design seems to be what people are measuring themselves by these days. I was surprised they were measuring grip strength competitively or working on it so much at all, but apparently it's a big new deal.

I did see some other grippers advertised here and there, with varying loads. Like up or down 10 pounds, etc., more or less harshly knurled grips, whatever. These ones I have are smoothly but well knurled; if you let your fingers or hand skin slip much, you'll definitely feel it, and maybe build up calluses.