Evans EC2S Frosted series contains two plies of 7mil film for optimized attack, tone, length of sustain, and ease of tuning for each size head. This drumhead features Sound Shaping Technology (SST) for a well-balanced sound, incorporated with Evans Level 360 Technology for ease of tuning, extended pitch range and optimum quality of sound.https://www.oosthavens.co.za/product-category/strings-things/things/