The Evans MX1 marching bass drum head is designed for outdoor AND indoor marching ensembles. This 22" white 10mil single-ply head produces a warm, mid-range dark tone. This tone can be manipulated by utilizing the included felt dampening arcs. These arcs can be affixed to the inside perimeter of the head, in any combination or pattern, to enhance articulation and focus the low-end.This head is available in sizes ranging from 14" to 32".