classic Drum machine it's all working some buttons need a hard press. early unit with smaller power supply fitting, the adapter is included as pictured. 9v power supply not included. The Alesis HR-16 is a vintage drum machine from 1988, showcasing a classic design with a 9-inch diameter and 16 pads for creating dynamic drum beats. Made of durable plastic, this digital drum machine offers programmable features for customised sound and performance options. With 6.35mm input/output ports for connecting to various devices, the Alesis HR-16 is a sought-after choice for musicians looking to add authentic analog sound to their compositions. Made in the United States, this drum machine embodies the quality craftsmanship and innovation synonymous with the Alesis brand.