I LOVE the recent upgrade they did to this product! I have large feet (16 US) and used to tear socks quite a bit with the last version of these. But! This new style is really well molded, with larger toes, and is WAY more resilient. Additionally, the extra toe room makes them far more comfortable, and they can be worn for hours. Good Job LatexCatfish!
We have a lot of zippers on our products here and a lot of options for zippers. A lot of times our patterns come with a pre-set selection, but we can customize more. Locking, WaterTight and even air-tight zippers are sometimes requested as customization features. You can always ask for a quote for something via the "I'd like to customize this product" link on any page. Meanwhile, here's a simple picture to explain the type of zippers and what they are called.