KitSound Audio Knit Bobble Cable Knit Beanie with Built-In Headphones - Cream? The KitSound Audio Beanie combines a stylish, warm beanie with in-built headphones that can be connected to your device through a 3.5 mm jack. With 40 mm drivers, your music will sound punchy with solid bass and retain clarity, detail and sound stage. So you can enjoy an excellent sound experience whilst keeping your ears nice and toasty. Comfortable and Warm with its stylish design and soft lining, this beanie is ideal for keeping your ears warm, while the adjustable speakers - which can be removed for washing - can be positioned to fit most head sizes. Specifications Compatible with all devices smartphones, tablets and MP3 players that have 3.5 mm jack Frequency response: 40 Hz - 18 kHz Sensitivity: 103 dB Box Contains KS Audio BeanieCable with volume control