When evaluating neoprene shoes, the material thickness (typically 1mm to 7mm) is the most critical factor, as it determines thermal insulation. For tropical waters, 1.5mm-3mm is standard, while cold-water diving requires 5mm-7mm. Ensure the supplier uses high-grade CR (Chloroprene Rubber) rather than SBR (Styrene Butadiene Rubber) for better elasticity and durability. Additionally, check for blind-stitched and glued (GBS) seams to minimize water ingress and vulcanized rubber outsoles for superior grip and puncture resistance.