Solid. Flexible and warm. The bootie fits well under my suit legs, no bulk. Snug and no excess material to fill with water. Interior is lined so getting them off is a breeze. The seams are welded so no splitting. I keep them cleaned with oneill wetsuit was and they don't stink up the garage. I only was with cold water to not dry out the neoprene. Excellent website and customer service on your side. I will only buy my wetsuits and gear here because you all really seem to care about high quality and treating me and my friends like family. I have been shopping here for 6 years now, best company around as far as I can tell.