>>76867326
my wrist don't get bigger, i can do 50 reps of these on max settings(60kg) but nothing

Based.
I had one or two COC grippers, but they are way too expensive and the engineering on them is actually fucking dogshit (the springs aren't coated so they tarnish, and they aren't spaced so they have internal friction).
You can get a full set (50lb to 350lb) of chink ones that are just flat out better quality in every way for just 20 bux.
>>76867336
Squeeze and hold for 5-15 seconds (or more) each rep. Your grip isn't designed to max out by pulsing. But these do not grow your wrists. Look at your arm and just squeeze your fist a bunch and you will see everything that contracts is just below your elbow.
If you want your wrists to grow, you need to do pronation and rotations and stuff. Basically everything that happens in arm wresting.

>>76867387
Interesting, I'll buy a non-chink one then

>>76867326
Don't waste your time with these. Get a fixed spring like Captains of Crush or a non-dogshit adjustable like GD Iron Grip. I had one of these and thought I was getting stronger fast before I realized the spring itself is so shit it loses tension within 2-3 weeks of use.
Also, be careful doing targetted grip training starting out if you are already going other things that require you to grip strongly like pull ups. You'll fuck your tendons ala tennis elbow.