Space where you are going to install it, activity to be carried out (indoor or outdoor) and light power to be achieved, as well as the number of light points and the surface and dimensions to be illuminated. Meteorological factors that may affect it. IK degree of mechanical resistance to harmful impacts and IP degree of protection required. Whether or not to include LED tube(s). If included, number of tubes to be housed (single or double screen). Type of thermal insulation cable and whether or not there is a power supply near the LED luminaire to be installed. Measurements of the light source(s) to be contained. Desired power, voltage and degree of regulation. Certificates you must have. Does or does not include warranty. In the case of a warranty, the number of years of validity of the warranty. Price and brand.