Memphis Audio 4" Convertible Coaxial Speakers MS42 M-Series speakers feature the same rich beautiful sound as before with even more versatility thanks to the new convertible design, allowing for multiple mounting options. Most MSeries models feature the ability to remove the tweeter and mount it as either a component set up or coaxial setup. This multi-function design allows a single speaker to do it all! If you're looking for accurate quality sound above all else, MSeries is the perfect fit. Features Size (in) 4" RMS Power (w) 40 Peak Power 80 Sensitivity (dB) 87 Mounting Depth (in) 1.75" Magnet Size (oz) 10 Grill included Y Coaxial design Carbon fiber cone External passive crossovers MClip crossover mounting solution Rubber surround Coaxial Design: MS46, MS42