This listing is for ONE Low Hours NUBM44-81 or NUBM47-A1 450nm 7+ Watt TO-5/9mm Laser Diode. The diodes are meticulously extracted from a new laser diode array. Buyer assumes all responsibility for it's use. *Optical output measured before the addition of a lens. You must know what you are doing before hooking these up. Reverse polarity, excessive current and high heat will damage or ruin these. A proper CONSTANT CURRENT laser diode driver is required to drive the diode. NEVER connect a laser diode directly to a battery or un-regulated power supply. The current should not exceed 4.5A CW. The diodes must be installed in to a laser diode module and heatsink before energizing to dissipate heat. A glass lens should be used as well. Be sure no dust, residue or other material is obstructing the diode window or lens. Each diode is tested for functionality before shipping. Always wear protective safety glasses or goggles that block this spectrum and intensity of light... You've only got one set of eyes!!! Most orders ship within 24 hours of purchase. Expedited shipping options are available upon checkout. Due to the volatile nature of electronics of this type, returns will only be accepted in original, sealed packaging. Please don't hesitate to contact me with ANY questions regarding my listing(s). I can offer a lot of technical assistance and/or point you in the right direction to find the answers you are looking for. I am usually very quick to respond and I'm more than happy to help. I will leave positive feedback once the transaction is complete. Please return the favor!