Alpine S-S40 S-Series 100mm/10cm/4" 2-Way Coaxial Car speakers (Per Pair Max 240|90 watts RMS) Fits UniversalAlpine S Series 280W Coaixal Speakers Supplied with Brackets to fit 4" Speakers to Universal 10cm spacer rings [<] The S Series delivers amazingly high performance for this class of speaker. They boast the worlds first use of a CFRP diaphragm (Carbon Fiber Reinforced Plastic), which has the ideal balance of hardness and light weight, for extremely clean and accurate sound. They also feature a larger voice coil than previous types for higher driving