Auch 4 Sets Shakeproof Wireless Handheld Microphone Anti-Rolling Mic Protection Silicone Ring & Bottom Rod Sleeve Holder Set for KTV Device, Multi-Colored It is made of silicon and it can protect your microphone from shocks, bumps, and falls. Also doubles as shock mount for your microphone. Use for wireless microphone protection, also identifies various stage microphones from the mixing board Inner diameter: 35mm Color: Grey, Black, Blue, Orange Package included: 4Pcs Anti-rolling Rings + 4Pcs Bottom Sleeves(Microphone NOT included)