Here's a PolarStar MRS for sale. Please read this if you are interested :) It's in absolutely great condition and works perfectly on my lower pressure tanks. Up around 4k psi, it starts to pop and hiss but when I keep it down, it is great and the refresh rate is amazing. If you have an SLP tank, this will 100% be great for you. If you have standard HPA tanks, just know that it's finicky at higher outputs.