Features: Bezel and grille design that clips magnetically into place, with the grille geometry being carefully optimized to ensure the perfect balance between sound and discreet appearance | The HF is adjustable by + or - 3dB from a switch on the crossover | 'UL94' flame retardant materials | Moisture proof | Q Install speakers come carefully packaged with installation template and fitting instructions | A cutter guide is supplied to mark out the hole you need to make | The speakers attach to your ceiling via four clamps you screw from the front | Speaker terminals have push open connectors that you can do with one hand | The grilles attach via magnets | Warranty : 1 year.