A spring-loaded coupling mechanism includes a cylindrical housing having a top and bottom end, a cylindrical interior cavity defining a top and bottom opening, and at least one uniformly integrated spiral coil. A height of the left front and right rear ground engaging supports is adjusted in a first direction. The control apparatus and the light-emitting diode are arranged on a common mount. Moreover, once the presence of the existing customer is known, location determining mechanisms may implemented to track the location of the known customer within or proximate to the place of business for the purpose of positively identifying the known customer. In the semiconductor light emitting device, the resin having fine particles mixed therein is composed of an optically transparent resin into which a large number of high refractive fine particles having a mean diameter of 100 nm or less and composed of a dielectric material are mixed uniformly to have a distance 200 nm or less between respective particles.