The DynamO is a hole-cutting template for resonant Bass drumheads that provides a vent hole for all drum mics. The DynamO is a laminated Mylar ring with a high-strength adhesive backing, providing added durability for the drumhead to prevent tearing when adding or removing microphones. Available in black or white individual size 5.5", and multi-packs of 5”, 7", 9". Also available in 4” black 10-pack.