Do you want to increase the amount of sound coming from your iPhone 4 without additional electronics? The AT&T/ Verizon Apple iPhone 4, iPhone 4S Silicone Horn Stand Case - Sky Blue is great for those who want improved audio without the cost. This silicone amplifier can increase sound by up to 13 dB and doesn't use batteries, plugs, or draw power from your mobile device! The naturally enhanced sound is complimented by the unique and attractive design that almost guarantees to get people talking!