Forearms/ Wrist Roller

I am trying to add muscle to my forearms. I have been doing hammer curls but just bought a wrist roller. What is the best way to incorporate the wrist roller? More frequently (3-4 x a week)? Do speed work with light weight or use heavier weights with lower volume? What are some routines you have had success with?

Thanks.

Frequently in general, but it depends on your current routine and your experiance and if you are doing big grip work already(powercleans,kettlebells,climbing ropes,etc). Is this for your forearm flexors or extensors or both?

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