This is the pressure switch
AquaTec Tank Pressure Shut-off Switch 80 psi 1/4" Quick Connect RO Reverse Osmosis https://www.amazon.com/dp/B00H0GUSJU/ref=cm_sw_r_cp_apa_WDm0BbTM6Z6TC
Another thing, the Solenoid valve, pump and pressure switch all come pre wired. The other issue is, instead of the Solenoid valve coming on with the timer it's only turning on with the switch instead of just the pump turning on and off with the switch?