O'Neill Wetsuits Heat 3mm Round Toe Boot Exterior and interior is made with fluid foam- a highly durable neoprene that resists abrasion and compression with a supple feel and good stretch- 50% stretch factor Glued and bandstitched seams Top shin strap- anti-flush Available in split toe and round toe Round toe features foxing seam weld and firewall insulation- a lightweight thermal insulation that wicks away moisture and increases warmth