The Parabola 1/2 Thermostatic & Pressure Balance Trim with up to 3 Functions from Riobel is a precision-made trim that allows you to adjust the temperature and pressure in your home. This trim also features a built-in 1/2" pressure gauge and a 3-function switch, allowing you to easily adjust the temperature, pressure, and fan speed. The Parabola 1/2 Thermostatic & Pressure Balance Trim with up to 3 Functions from Riobel is a precision-made trim that allows you to adjust the temperature and pressure in your home. This trim also features a built-in 1/2" pressure gauge and a 3-function switch, allowing you to easily adjust the temperature, pressure, and fan speed.