REMOVABLE INSOLE EXTRA COMFORT LWG - SUSTAINABLE Upper: 100% calfskin leather Inner lining: 75% pig skin and 25% textile Sole: 100% synthetic EXTRA COMFORT REMOVABLE INSOLE Type of close: Elastic Thickness of the sole 2 cm (0.79'') The Memory Foam insole contains 85% recycled material. Maximum arch and heel comfort due to arch support technology giving extra cushioned support