The Turbo Valve is one of the best selling tuning parts for the Spyder/Speedster. Made from stainless steel it drastically improves efficiency and allows the marker to work with a much lower working pressure and a weaker mainspring for less wear. Less kick, many more shots from each CO2/HP tank, less ball breaks and better accuracy due to consistent velocity are the positive effects. Including Valve O-Rings.
The Pro Toyz Turbo Valve is older, so while it may be available used and in a few cases new, it is not commonly available anymore.