Bo for this competition was made of hollow alluminium stick, which was covered with isolation foam. These bos were relatively fast but from my point of view quite dangerous, especially for less experienced fighters. On the tournaments organised by me, we use hollow plastic sticks covered with isolation foam. These bos are a bit thicker, the weight is more or less the same, but their safety is high. Some of them get broken during the tournament but as I say, better 15 broken soft bos than 1 broken arm or leg:) There are bruises, of course, the hits are quite felt, but no serious injuries. However I always work on different enhancements and with new materials suitable for soft bo. If you have more questions, let me know, I am happy to answer.