Z-CoiL Pain Relief Footwear Women's Olivia Black Boots Built-in rigid Z-Orthotic to protect and support plantar ligaments, reducing the pain of plantar faciitis, heel spurs, and arthritis. Patented conical heel spring - the Z-CoiL - to reduce up to 50% of impact as it eases overall fatigue and back pain. 3/4" forefront cushioning shields delicate toe joints, ligaments and tendons, while a wide toe box relieves joint pain and pressure. Genuine full grain soft leather accommodates every curve of the foot. Rubber sole for additional slip resistance