The Vocal-Star VFM twin VHF radiomic system is ready for use straight out of the box. The kit consists of 2 Radio mics on different frequencies for interference-free operation. 1 x Twin Aerial Radio Receiver, Power Supply ,1 x 1/4" Jack - Jack cable & 2 x 9v batteries. The VS-VFM is a great piece of kit for the price. Max range up to 50m. like with any wireless microphone set , The microphones needs to be connected to a speaker karaoke machine PA to produce sound, this does not have speakers built in. Please note these are not professional microphones, But Goood Value For Money ( VFM )..