Of course it is good, I plan to buy it myself soon also, its good for training and strenghtening joints if you are doing warming up, its like with any other sports, good warm up always helps to avoid injuries immensely.
Also don’t start punishing with max power from the very first punch, do it like with meditation, like start easily and light and build up gradually.
Here is very nice exercise to strengthen tendons this should be benefit for punching, I very liked it: