Code drum heads are purpose-built, designed by drummers for drummers. They have matched time honoured and trusted manufacturing techniques with up to date cutting edge technology to produce a new premium range of drum heads. All their heads use the highest quality PET polyester film, kept securely in place by Code's revolutionary Grip-Tight rim technology. This unique innovation features a deep, double-knurled solid steel core securely crimped by a high-quality aluminium rim, to ensure the head stays put while you play. It also allows the head to resonate freely, tune easily and super quick, and hold its tuning longer. Plus, all materials used to manufacture Code products are 100% recyclable. Code Enigma series bass drum heads have a single ply of 7.5 mil PET film for use on resonant (outer) side of your kick drum. They feature a clear underside dampening ring to help control overtones and dampen sustain. Available in Black or White. Available in sizes 16-24".