Applicable hair: soaked and dry Thermal conductor product: environmentally friendly alloy Thermal conductor diameter: 16MM-20MM Temperature Regulate adjustment: 3 sections These needles are the proper size, and may not puncture the liners if appropriately used WARNING: Product or service cannot be returned or exchanged if liner is harmed or punctured https://riddell-speedflex-adult-l85505.blogocial.com/about-speedflex-adult-large-66671632