Fresnel Lens Large, 300x300mm, Focal Length 300mm, Acrylic Lens (not Glass),Olar Death ray for Physics Classroom,Magnifiying Sheet Fire Starter for Solar Heating, Solar Oven.

Bought this as a gift for my friend. We used it to successfully heat up a block of titanium. We weren't able to melt it, and it stayed in pretty good shape.... Unlike the rock.

The items were well packaged and arrived in good condition.

Likes. First year I didn't buy gift cards. Adults and kids liked it. Fun and something to learn about. Magnifier for fun and start a fire for the survivalist. No one knew there was such a thing as a fesnal lense. Made of good, plastic, should last long time if taken care of. Well packaged.Nothing to dislike, just present as learning opportunity with a couple of demonstrations every one will be excited.

I bought this to heat water during the winter outdoors. Works great! When used with a black rubber bucket, and the correct angle.

The center of the light is going to be super bright so don't stare at it and be sure to have good dark sunglasses.it It really works.

The packaging for the lens was great which protected the lens easily and works well as a storage container for the lens. The lens came in pristine condition and was completely clean and clear and if you focus it right it can get stuff extremely hot! It’s a really cool piece for experiments or just messing around.

...great for science projects. It took less than 1 second to begin charring old snail shells, maybe two before flames were seen. I was expecting it to be thicker just from the image shown, but that's an optical illusion...it is the 2mm they promised (it's clear in their picture of it in someone's hands holding it at an angle). 2mm is a reasonable thickness, not too heavy, not too expensive, not too fragile.Someone wondered about pennies, so I couldn't resist an experiment. I placed a new object (cheap materials, not to be confused with the older copper ones) over a crack in the sidewalk, donned sun-glasses and held the focal point as best I could for 3 minutes. I was forced to end my experiment at this point, because a furry critter became very curious and I didn't want them to get their paws anywhere near the area, or hurt their eyes.My observations are:1) You really need better than sunglasses for eye protection. Don't even try without at least two pairs. Think of it in terms of welding.2) these new objects are weird. It still seemed flat on the top when I had to quit, yet when I picked it up a little later (after removing the furry critter to a safer area), I saw that it had indeed melted into the crack even though the top surface remained fairly flat - only drooping over the gaps on the two edges where the crack was. The top surface was also noticeably thinner. I surmise that this lens effectively softened the two outer layers of material, making them pliable, and melted the middle layer of material, allowing it to pool in the center where the crack was.In short, this lens can indeed, melt metal.

I saw all these reviews that you could use it to make a fire and I tried it numerous time with my children and it never worked. Could be user error.