The sides feature a snap button option to adjust to a tighter or looser fit on these overboots. Here are some important details for the Overboots : SIZE: Xl, COLOR: Black, GENDER: Men's Features Closure Type: Snap Waterproof: Yes Footwear Closure Type: Snap Tab Predominant Footwear Color: Black Resists: Chemicals Fits Shoe Size: 15 to 16 Color: Black Upper Material: Natural Rubber Gender: Men's Footwear Sole Pattern: Molded Boot Height: 17" Outsole Material: Natural Rubber Toe Type: Plain Metatarsal Guard: No Style Number: 178 Midsole Material: Natural Rubber Typical Overboot/Overshoe Application: Moderate Chemical Resistant Height: 17" Item: Overboots Size: Xl Rubber Boot Style: Knee Material: Rubber