The above product is used in the basic study of optics in schools, colleges etc. the products is avaible in various models like 6", 7", 10" etc. with in built light source or without light source also as per user requriement. The light arrangement in the instruments is provided so that student can read the scale easily. 
There r many other optical instruments also that can be suuplied like telescopes, microscopes etc.. The equipments supplied by us r of good quality & r widely used in various reasearch labs also.