The UV-1 light bar is designed to be used on the Model-H/W. It adds a certain portion of the UV spectrum to completely mimics the properties of natural sunlight. UV will increase terpene production which improves the smell and flavour of herbs. One UV-1 bar produces 70 watts full spectrum light plus 10 watts supplemental UV light. It is recommended to swap two bars for a 4’x 4’ or 5’x5’ coverage in the last 4 weeks of the flowering cycle.