since you have almost no size, why not take care of multiple things, and learn how to deadlift? It will tax your entire body (including your forearms) and is much more productive than focusing on just wrist curls/isolation forearm exercises. Check out starting strength, read up a bit on technique, and begin focusing on compound lifts like squats, deadlifts, bench, and overhead press.
+1, he has the right idea.
this is the best solution.