Make the ultimate and fastest Boxing Cobra Punching Bag with the ultimate Kewlus PRO Spring: the KSR12PRO. Increase the speed to your liking, yes speed is adjustable! This spring is designed to fit easily onto a 3/4 inch pipe and simply held in place with a butterfly hose clamp. Increase the speed by moving the spring lower onto the pipe, thus reducing the number of active coils.
For complete DIY build instructions including a video using the Kewlus PRO Spring, go to https://kewlus.com/blogs/diy/how-to-make-pro-cobra-punching-bag.
Review & Build by CSquared Boxing
Check out one of the top boxing gear reviewers on YouTube, Carlo Rosauro to see his hands on take on the spring as well as his full build https://www.youtube.com/watch?v=55FD41ie3ns
Kewlus PRO Spring Community
Check out the Kewlus PRO Spring Community page to see how others have setup the Kewlus PRO Spring cobra punching bag!