I was sceptical about spending 600 bucks for these 2 stickers, but still went ahead and bought. I must say these really work ! The sound of your bass drum improves & it helps in reducing the extra bounce on the batter head when you hit hard.. Bought them recently so can't say much about the durability. Its Evans, so they should be durable though.Thanx Bajaao for the quick delivery & service..