Purchased a size S on Amazon for around 5299 yen. Used 2-3 times. Disinfected. Solo karaoke Loud voice Noise prevention Apartment complex Condominium Apartment Complaint measures Vocal damper Soundproof mask Vocal training soundproofing goods Stress relief goods Shouting Singing practice Soundproof karaoke Warm-up Portable Odorless Soft Silicon voice silencer