Manufactured using Poron Xrd technology on an EVA Thermoformed base Woof Wear's new Smart Knee boot provides exceptional protection to the delicate knee joint.An anti-slip top band and adjustable base strap ensure a secure fit and prevent the boot from slipping or spinning.The inclusion of Poron rd foam in the key strike area means that the PU Shell can be more flexible and therefore more comfortable than other products on the market because on impact the Poron Xrd foam stiffens to give added protection. Woof Wear call this 'Protection on Demand'.The Smart Knee boot is suitable for hacking especially on the road and travel. PU Shell. Poron Xrd in strike area. EVA Thermoformed Base which flexes with leg. Anti slip top band. Adjustable base strap.