A common use for smaller (3/4 inch inside diameter; 4.75 inch outside diameter) rings is to wear on the wrists while practicing sets, blocks and punches. The ring shown below weighs 1.35 pounds which does not sound like much until you are several minutes into a vigorous Hung Gar set or are doing 1,000 punches. I am not altogether sure what happens if you block an incoming punch while you are wearing rings. If you still have enough speed to intercept the enemy punch I’d imagine his forearm will be painful.
The rings described are for experienced students. The medium-sized versions are 1.15 pounds with 3.25 inch inside diameter and 4.375 inch outside diameter. The limiting factors are being able to get your hand through the rings and not having the rings slip off when you punch or block.
According to Grandmaster Wing Lam “when you strike with real power and speed, the rings make a distinctive sharp clang that any genuine master will recognize as true kung fu skill”.