(12) Damping tiles for sound and vibration reduction. 12 x 12 x 3/8. These are similar to Decidamp, weigh 3.2 pounds a piece and are semi flexible. MIL-P-23653 C, MFG P/N : 8899-128, P/N 211065076. These should work good for audio and stereo speakers. I can ship 12 in a large flat rate box so if shipping is high send me a message and I can adjust shipping.