XL black apnea socks with a comfortable fit, 1.5mm thick. - Brand: GULL SKIN - Model: GA-5653 - Size: XL - Color: Black - Thickness: 1.5mm ⭐︎Purchased about 2 years ago, but never used and stored away. Wearing fin socks with a thickness of 1.5mm is comfortable as it prevents blisters when wearing fins with bare feet. ☆I would like to sell it to someone who can use it. Thank you for looking.