Aquarian Black Bass Drum Portal Hole (5" Diameter) An adhesive backed hole cutting template for front bass drumheads. Available in black or white with a 5” hole.
By snapping these rings into your bass drum resonant head's hole, you can help extend the life of the head! It also can help protect the hole edges during transport as well as if an engineer wants to insert a microphone into the bass drum. Try these rings to give your head a tighter
Bass Drum O's HC4 4" Chrome Bass Drum Hole Reinforcing Ring When it comes to venting and porting, Drum Os gives you plenty of options. Its easy to get creative with Drum Os because there are endless design possibilities.