Fit. The openings and the screw holes are the NEMA standard's — a rocker plate's 33 × 67 mm window with screws 96.8 mm apart, a toggle's, a duplex outlet's two D-shaped openings with the screw between — on the standard 46 mm gang pitch, so the plate goes straight onto the device that is on your wall now, with its own screws. The back is flat; the face carries the relief and the countersinks. PETG, not PLA: a plate sits over a dimmer that runs warm and takes a screw cinched down hard on a thin rim — PETG holds its shape to about 80 °C and flexes where PLA would crack. Wipe clean with a damp cloth.