Anyone?..I made mine out of part of an old bed frame and some old wire. (just used what I found in the shop.)
I hear these are killer for the forearms. Killer Jerry; killer. 
~LV~ said:You really dont have to work forearms directly, if hypertrophy is your main goal.
If you are strength training then I'd say you can do specific forearm exercises however, if you are doing movements such as deads, rows, hammer curls, lat pulldown, etc....your forearms will get more than enough stimulation to grow.