A set of 23 aluminum sheets for deadening, available in silver and blue. The front is an aluminum plate, the inside is a butyl rubber plate, and the back is tape. These are cut from large sheets into easy-to-use sizes. Please note that the sizes are approximate. You can also cut them smaller with a utility knife. - Color: Silver, approx. 25cm x 5cm, 1mm thick, 11 sheets - Color: Blue, approx. 15cm x 5cm, 2mm thick, 12 sheets - Material: Aluminum - Application: For deadening - Quantity: 23 sheets total - Weight: Approximately 800g total This is 4 times the weight of similar Aimon products, making it a great value at this price.