The Evans System Blue tenor head has a 2-ply design with 7mil top-ply and 7.5mil bottom a combination that delivers tonal clarity and projection while also increasing durability and pitch stability reducing the need for frequent tuning. The System Blue series uses Evans unique Sound Shaping Technology a damping technique that targets unwanted overtones and provides the control needed to enhance attack projection and note definition. The damping pattern on each head also provides a visual reference for the optimal ˜playing zone for each drum offering a target for less experienced lines.