Comprising a long wooden baseboard about 100cm x 10.5cm, with a scale graduated in millimetres fixed on board. Provided with 4 free sliding bases riders  100x50 mm with index marks on one side of the base, for mounting accessories, with heights of the accessories adjustable with index marked on one side of the base. Accessories include 1 Wooden baseboard, 2 Lens  holder, 2 Object Needle,  4 Riders.