The most powerful UVB light we offer. Has integrated timer with automatic-off integrated for controlled, limited exposures. Detailed instructions included. Up to 8x rate of effect from UVB vs. same exposure time in maximum sunlight (sun has much higher ratio of UVA to UVB). UVA counteracts actions of UVB by several means including short-term melanin production and destruction of epidermal vitamin D. Melanin production from UVB indicates over-use. UVB germicidal light aids production of certain photo-products that only UVB light exposure on chemical pre-cursors resulting in chemical reactions and DNA / RNA damage. UVA reaches deeper dermal layers in most animals and reptiles than. UVB is absorbed in outer layers where UVA continues to penetrate. Both react in collagen, and dermal layers where cells reproduce. Powerful UVB germicidal and UVA by-product light. Caution: not a sunlamp, not a tanning lamp. Recommended for germicidal/laboratory/private use only, not a medical device. Limit timer switches off automatically after 0-60 minutes by setting. Model 2 Rayminder lamp with mid-range UVB delivers powerful UVB exactly where, when, and for how long it is needed. Portable, mountable fixture with integrated timer now with rubber legs for table top use. Glasses included free with shipment are rated for UVB filtering. Lamp has electronic ballast perfectly engineered for the bulb for instant-on, hum-free, non-flickering, quiet operation. UV bulbs contain a loose inner metal piece that will rattle when moved by design. Mounting fixture has reflective strip under the installed bulb. 5' 120v polarized plug cord. This powerful UVB lamp starts killing germs on illuminated surfaces and in nearby air within seconds. Works best to purify hard-to-clean surfaces like keyboards, where germs thrive indoors. Cleans in minutes how hours of sunshine would! Ships with bulb and timer installed, instructions, UV glasses, UV detecting beads. Production is limited, get your order in now!