Eisco Optical Glass Concave Lens, 200mm Focal Length, Top Spinning Base, 3"

I got my nephew a professionally spun and tuned spinning top for Christmas. These lenses were recommended for use as a base on which to spin the top as the gentle concave shape keeps the top towards the center and the glass surface provides a smooth surface with little friction. Using this as a base he was able to spin his top several times that night for 4 to 5 minutes and it spun so perfectly it would often hardly look like it was even spinning.

Bought this Eisco Optical Glass Lens to help me with my art projects and I am delighted by the quality of the lens. Wondering if there is a holder available for it. Bought two more for friends in my class.

As an artist, This works to view a painting while close to it, instead of backing away; Invaluable in tight spaces. Art supply stores used to sell them as reducing glasses with handles and band around the glass. Hard to find. This works.

Product was exactly as described and made very well

I have no idea what was responsible for the complaints that others have experienced. My lens arrived in what looked to me to be perfect shape in spite of obvious (mis)handling of the package. This lens is a much better base for spinning Forever tops than the one provided at a much higher price by Forever Spin. Unlike the commercial product, the lens not only seems to keep the top spinning longer and more centered, at the end of every spin, at least so far, the Forever Spin Titanium top stays in the lens when it drops. Sometimes the excess energy is depleted by a rocking motion that sounds a bit like a ticking clock and is tres cool. I will soon try my Vorso top in it and see if it just a one top base or a universally great deal.

It's just OK.. I'm a newbie when it comes to spinning tops. This lens is a great idea, however the edges all around are sharp which puts bad scratches in the bottom or your tops. The edges needs to be covered in some manner. Like a rubber wrist band, or tape. I wish someone would have told me.

I got this on a whim for some spinning tops and a cotton supported spindle. It works well for the tops, but I think I need more practice for the spindle. It's been a cool item to interest my grandkids with the optical effects. The lens is very well done with clean smooth edges. I have used it at work to clarify engineering drawings after I noticed the lens making some parts of the drawing clearer even though it was making it smaller; counter intuitive but handy.

I am using it to check proportions in my drawings and paintings

The glass was cracked when it arrived.