Gigastone KM-6500 Silver Bluetooth Connection Speaker/Microphone Home Karaoke Bluetooth connection works without issues. Echo works without issues. Bass and treble adjustments? The speaker unit isn't top-of-the-line, so the effects aren't very noticeable. Fast forward and rewind functions change YouTube to the next or previous song. The 3.5mm jack at the bottom is for external output. Charges via MicroUSB. There's a USB port, but its purpose is unknown. Can be used as a Bluetooth speaker. Perfect for outings or stress relief with home karaoke! How about it? There are no major scratches or stains, but there are minor scratches and dirt. I hope someone who needs it will use it. Please refrain from purchasing if you are sensitive to used items. My other listings related to home appliances: #hisapa家電 Compact wireless microphone with Bluetooth connection. Features volume and echo adjustment. - Brand: Gigastone - Type: Wireless Microphone - Color: Silver - Features: Volume adjustment button, Echo adjustment button - Connection method: Bluetooth connection - Features: Compact design, convenient to carry - Microphone shape: Handheld microphone Thank you for viewing.