Tested and works 100. The Roland Micro Cube GX Guitar Amplifier in black is a compact and powerful combo amplifier designed for electric guitar practice. With a single speaker and channel, this amplifier from the renowned brand Roland offers versatile sound for musicians looking to enhance their practice sessions. The sleek black design adds a stylish touch to the portable and easy-to-use amplifier, making it a must-have for guitarists looking to improve their skills in a convenient and affordable package.