2 x Pairs Install Bay 1200Hz 3.5" Bass and Treble Blockers Bass blockers are a must whenever replacing the factory speakers in your vehicle. These will protect your speakers and will help keep them from blowing. These bass blockers will remove unwanted low frequencies from getting to your speakers allowing them to play the frequencies they were meant to. After installing these your speakers will not only sound clearer and more crisp but they will also play louder. Easy installation will protect your speakers allowing them to play for years to come. The recommended speaker size is given for a standard car audio speaker which is 4 Ohms. Quantity: 2 Pairs Specifications: Pair of bass blockers Removes low frequencies from the audio source Frequencies blocked at: 4 Ohms: 0-1200Hz Protects the speakers from receiving damaging frequencies Recommended for use with larger speakers Compact size for easy installation ?Can be used for car or home audio 3.5" Speakers