These aren't anywhere as thick as those other grips but I like using these and they increase the grip a little bit. I originally saw them in an article by Eric Cressey so I figured why not? I really like them if you only have a thin bar for pullups and throw these bad boys on there. I've been using them for DL's and rows as well.
"And for crying out loud. Don't go into the pain cave. I can't stress this enough. Your Totem Animal won't be in there to help you. You'll be on your own. The Pain Cave is for cowards.
Pain is your companion, don't go hide from it."