Chiropractors have acknowledged our products stress relieving effects on people with joint and muscular conditions. Veterinary clinics also rave about these effects on animals with similar health problems. Wacky Walkr products are available in 4 sizes corresponding to animal weight ranges, 4 configurations for specific walking environments and 14 distinctive colors. We are confident you will find this system to be an exceptionally comfortable pet walking experience and we stand by our promose.. we won't jerk your chain.