$29
5" x 12" average to 7" x 19"
7-12 scraps per lot.
THESE ARE HEAVY DUTY LENS SCRAPS
NOT CONSUMER PAGE MAGNIFIERS.
THERE IS A BIG DIFFERENCE.
GREAT TEACHING AID
TEACHERS CONTACT ME FOR HIGHER VOLUME
SMALLER PIECES FOR CLASSES
Lens in good condition with a few minor scratches and scuff marks
Note: This photo is similar to the lens you will receive. The power ratings are accurate and the only difference is minor scratches etc.
SOME HAVE A BIT OF TAPE AROUND A FEW EDGES
ALL THE LENSES ARE OFF CENTERED. ALL CONCENTRATE SUNLIGHT.
THESE REDIRECT LIGHT INCREDIBLY AND CAN BE ARRAYED TOGETER TO
MAKE ONE COMMON FOCAL POINT. TAKES SOME WORK.
THEY CAN ALL START FIRES SO THE WARNINGS ARE THE SAME.
COOL LIGHTING EFFECTS
WARNING : I have included a Youtube video to demonstrate the power of this type of lens when placed in the sun. The lens should NEVER BE LEFT IN THE SUN UNATTENDED. Fresnel lenses concentrate several square feet of sunlight down to less than 1/2". My personal tests have resulted in surface temperatures in excess of 2000 degrees fahrenheit WITH A SPOT LENS AND 900 degrees fahrenheit WITH A LINEAR LENS. VERY DANGEROUS. IF YOU DO USE THIS FOR SCIENTIFIC PURPOSES, DO NOT LEAVE OUTSIDE OR NEAR SUNLIGHT EVER. TREAT IT AND RESPECT IT AS A FURNACE OR BLOWTORCH. Stuff instantly can catch on fire. Buyer assumes all risks and agrees that separating the lens from the protective cover is done so at their own risk and responsibility. If you are crazy enough to use this for sun collection I strongly recommend wearing protective eye goggles (wielding/blow torch) to prevent eye damage. Protective clothing (fireproof) is also recommended as well as a large open space away from structures and autos. CHILDREN OR PETS SHOULD NEVER BE IN WORK AREA! By bidding on this item, buyer agrees to accept all responsibilities and AGREES TO hold seller harmless from injury or damages resulting in the use and possible mis-use of this item. MUST BE 18 years or older to purchase.
AGAIN!!!!!!!!!!!!!
WARNING : I have included a Youtube video to demonstrate the power of this type of lens when placed in the sun. Lens should NEVER BE LEFT IN THE SUN UNATTENDED. Fresnel lenses concentrate several square feet of sunlight down to less than 1/2". My personal tests have resulted in surface temperatures in excess of 2000 degrees fahrenheit. VERY DANGEROUS. IF YOU DO USE THIS FOR SCIENTIFIC PURPOSES, DO NOT LEAVE OUTSIDE OR NEAR SUNLIGHT EVER. TREAT IT AND RESPECT IT AS A FURNACE OR BLOWTORCH. Stuff instantly can catch on fire. Buyer assumes all risks and responsibility. I strongly recommend wearing protective eye goggles (wielding/blow torch) to prevent eye damage. Protective clothing (fireproof) is also recommended as well as a large open space away from structures and autos. CHILDREN OR PETS SHOULD NEVER BE IN WORK AREA! By bidding on this item, buyer agrees to accept all responsibilities and AGREES TO hold seller harmless from injury or damages resulting in the use and possible mis-use of this item. MUST BE 18 years or older to purchase.WARNING : I have included a Youtube video to demonstrate the power of this type of lens when placed in the sun. Lens should NEVER BE LEFT IN THE SUN UNATTENDED. Fresnel lenses concentrate several square feet of sunlight down to less than 1/2". My personal tests have resulted in surface temperatures in excess of 2000 degrees fahrenheit. VERY DANGEROUS. IF YOU DO USE THIS FOR SCIENTIFIC PURPOSES, DO NOT LEAVE OUTSIDE OR NEAR SUNLIGHT EVER. TREAT IT AND RESPECT IT AS A FURNACE OR BLOWTORCH. Stuff instantly can catch on fire. Buyer assumes all risks and responsibility. I strongly recommend wearing protective eye goggles (wielding/blow torch) to prevent eye damage. Protective clothing (fireproof) is also recommended as well as a large open space away from structures and autos. CHILDREN OR PETS SHOULD NEVER BE IN WORK AREA! By bidding on this item, buyer agrees to accept all responsibilities and AGREES TO hold seller harmless from injury or damages resulting in the use and possible mis-use of this item. MUST BE 18 years or older to purchase.WARNING : I have included a Youtube video to demonstrate the power of this type of lens when placed in the sun. Lens should NEVER BE LEFT IN THE SUN UNATTENDED. Fresnel lenses concentrate several square feet of sunlight down to less than 1/2". My personal tests have resulted in surface temperatures in excess of 2000 degrees fahrenheit. VERY DANGEROUS. IF YOU DO USE THIS FOR SCIENTIFIC PURPOSES, DO NOT LEAVE OUTSIDE OR NEAR SUNLIGHT EVER. TREAT IT AND RESPECT IT AS A FURNACE OR BLOWTORCH. Stuff instantly can catch on fire. Buyer assumes all risks and responsibility. I strongly recommend wearing protective eye goggles (wielding/blow torch) to prevent eye damage. Protective clothing (fireproof) is also recommended as well as a large open space away from structures and autos. CHILDREN OR PETS SHOULD NEVER BE IN WORK AREA!
NEVER STORE EXPOSED LENS NEXT TO ANY STRUCTURE!!!!!!!!!!
NEVER LEAVE LENS UNCOVERED WHEN NOT IN USE!!!!!
By PURCHASING this item, buyer agrees to accept all responsibilities and AGREES TO hold
seller harmless from injury or damages resulting in the use and possible mis-use of this item.
MUST BE 18 years or older to purchase.
THIS IS NOT A TOY, REAL SCIENCE STUFF!!!!!