A method and device utilizing touch screen transparent LED means is shown for viewing a number of products, selecting one or more for investigation by displaying information concerning the selected items, choosing one for removal from the display of items and delivering the chosen item to a user. The fluid sampler is actuated to establish fluid communication between an interior and an exterior of the fluid sampler such that a fluid sample is obtained from the well in a chamber of the fluid sampler. When two amplifiers are used to drive the voice coils, the sequence of connections of the amplifiers matches those of the voice coils mentioned above. The rod inserts through the connecting member, the springs, and secured in the receiving recess such that the battery cover can rotate about the rod. A method of fabricating and aligning the guide block assembly is also disclosed.