Design: Our Bass Drum Bottom Port Hole Protector Rings is a must have drum accessory, designed to protect your drum skin. Material: Drum accessories is made of PVC material, this Hole Protector Ring is sturdy. Replacement: Nice replacement for your old or broken parts. Easy to Use: Easy to install and remove, this drum accessory is a practical addition to any drum set Practical: With its sleek design and premium material, the Bass Drum Bottom Port Hole Protector Ring not only protects your drum but also adds a professional touch to your drum set. Size Chart: Inner diameter: 13.5cm/5.31in Outer diameter: 18.8cm/7.40in Package Includes: 1xDrum Bottom Port Hole Protector Note: Please allow slightly errors due to manual measurement and different monitors.