The hard, but very durable core of the stick is covered with a layer of flexible foam, two layers of plastic, and hemmed with a thick, abrasion-resistant cover. Thanks to this structure, our sticks can withstand even sharp sparring matches without breaking, while dampening the force of blows quite well. We know because we have been pairing them ourselves for over a year - you can see what it looks like in practice in the videos below or on the YT channel of the Sunday Sparring Meetings, where we have been practicing with them since 2019.