Personally, the summer suited me well, it has a connection attachment with the mask so that it remains stable. Comfortable mouthpiece and lightweight.

To me, it has a strange inclination when I apply it to the mask's rubber and it is annoying. No matter how I put it, I didn't find it comfortable.

Very good. I bought 2 because we are a couple that goes to the sea. The soft silicone mouthpiece makes it very comfortable to use. The only downside is that where the mouthpiece attaches to the respirator, it let a little water in on one of the 2 due to the rotating joint it has. However, it sealed with a little almond butter

Impeccable in its simplicity. The two characteristics that make it perfect, both for free diving and underwater fishing, are its elasticity throughout the length of the tube (it is very soft, it can be folded even twice for storage / even without a clip if you pass it under the mask strap it is very comfortable / at high speeds, water resistance simply bends it, without hitting the head or bouncing), as well as its careful design that makes it self-draining during ascent (with the water outlet at the end of the dive it empties on its own, without the need to blow, meaning that by putting it back in your mouth you can inhale completely fearlessly). There is absolutely no reason to spend more money on more expensive valves. After all, it is no coincidence that top athletes in free diving recommend it.

One of the best in its category, it does exactly what it says. Comfortable breath, very flexible... good purchase