They are called Fish Masks. They come in a few different sizes and you have to buy the corresponding "Living Eye" to go with. These are tied on a Mustad stainless 1/0 hook. (I may take them to the salt). The mask is just hard plastic and is designed to be neutrally buoyant. I did this one with buck tail and a little white sculpin wool underneath. I'm thinking of a few kinky variations on colors, size and stinger hooks etc. I used a heavier red monocord and some super glue to hold it all together. MUCH easier than those old epoxy head streamers.