ClsceaPMMA CO2 Diffuser with Integrated Bubble Counter for Aquarium Plants (L)

Does anyone have the actual link for a replacement disc for the clscea stainless steel co2?

is 50 psi to much for this diffuser my regular does go below 50psi?

How do you know which size you need?

what gallon tank does this work with? is it too small for a 75 gallon tank?