Horizon Light Therapy Unit is the treatment surface plate is roughly 2 in diameter. The Horizon Infrared and Red Light Therapy unit conveys a powerful 800mW of infrared and red light with 36 infrared super luminous diodes and 7 visible red super luminous diodes. The standalone power supply has two keyhole mounts on the backside of the enclosure enabling it to be mounted to a wall. This lightweight design eliminates operator fatigue and makes it easy to transport. The entire unit weighs 2lbs 8oz. with the probe handle weighing only 8 ½ oz. The standalone Horizon was leading to be lightweight, durable and portable. The Horizon probe can be purchased as a plug in to the new HF54 Hands Free Ultrasound or separate as a portable standalone. A dose of 4 J/cm2 takes a light over 90 seconds.