Superior quality glass lenses are useful for teaching a variety of optical principles. Double concave lenses have two inwardly curved surfaces, a negative focal length, and are often used to aid in the distribution of light, as well as, image reduction.

International Data
HTS Code	9001905000
Country Of Origin	China
Product Code
UPC-12	795721144651

38mm D x 10cm Focal Length - Double Concave

Product Code: 7-909-8

$1.15

Qty

0 reviews / Write a review

Specials

10 Gallon Aquarium

This strong tanks feature welded angle-iron frames, with a non-corrosive baked-on finish suitable fo..

$49.99 $99.99

12" Banana Plug (both ends)

Banana plugs are safe and easy for students to use. The connectors are soldered to the insulated lea..

$1.29 $1.49

12" Banana Plug (both ends)

Banana plugs are safe and easy for students to use. The connectors are soldered to the insulated lea..

$1.29 $1.49

12" Banana Plug (both ends) - 3 Black, 3 Red

Banana plugs are safe and easy for students to use. The connectors are soldered to the insulated lea..

$7.96 $10.49

12mm Beads- Plastic, 500ml

Plastic styrene beads for plastic column kit. For grades 6 to 12. Measures 12mm diameter by 500ml si..

$20.99 $49.99

25mm D x 75mm L x 200mm Tl, Nylon, dz

It is a good practice to replace your brushes regularly to prevent scratching your glass and plastic..

$3.24 $6.49

30ml Cap 50mm Rim Dia x 30mm Bottom Dia x 30mm H

The porcelain casserole is made to withstand high temperatures when used for melting or drying ingre..

$1.29 $1.64

36" Alligator Clip (both ends)

Alligator and banana clips are safe and easy for students to use. The connectors are soldered to the..

$1.79 $1.89

36" Alligator Clip (both ends)

Alligator and banana clips are safe and easy for students to use. The connectors are soldered to the..

$1.79 $1.89

3D Reindeer Craft Kit

A perfect cold and snowy day Christmas activity project! Simply pop out the precision cut 3D model..

$4.99 $9.99

3D Santa and Sleigh Craft Kit

A perfect cold and snowy day Christmas activity project! Simply pop out the precision cut 3D model..

$4.99 $9.99

6 Gallon Aquarium

Your classroom aquarium can serve many purposes but, above all, it should be thought of as an instru..

$39.99 $74.99

76mm White -20 To 110 Deg C - Clear

Thermometer, Red Alcohol, White Back, Total Immersion, -20 to 110 deg. C, 300mmL. A total immersion ..

$2.19 $2.34

A Jumble In The Jungle

Every page contains two pictures that seem to be identical but, in fact, contain a number of discrep..

$1.99 $2.99

ABIG Block Printing Paper 20 Sheets, 905

This pad of 20, linoleum and block printing paper, measures 9" X 12".Ideal for Lino Block, Wood Bloc..

$14.99 $19.99

Acids and Bases Kit

This kit allows learners to perform investigations on the properties of acids and bases. They also s..

$74.99 $149.99

Acrylic Equilateral Prism; 3" x 1"

Prisms are essential tools for teaching about light refraction and dispersion and come in a variety ..

$4.29 $4.74

Adaptation

Scales-Guppy (40x) • Dogfish (100x) • More Scales-Lizard(10x)/Bird(20x) • Frog Skin (160x) • Flight ..

$8.99 $9.50

Additional Game Mats/Markers/Die

Original games by the authors of the Fraction Bars™ program allow your students to have fun while le..

$7.99 $10.49

Advanced Geometry - Bingo Bus™

Get on Board the Bingo Bus™ ! The well-loved game of BINGO is transformed into fun topics for Math. ..

$15.49 $16.99

Adventures Around the Universe Shapemaker Fun

Each page in this booklet contains two pictures; one complete with transportation and one incomplete..

$1.79 $2.49

Air Pollution and Plant Health

Pore in Leaf Epidermis (430x) • Air Spaces Inside Leaf (480x) • Salt Particles from the Air (8400x) ..

$8.99 $9.50

Air Shape Ball 36

A great alternative to cage balls, air shape balls provide feather-light fun. Shapes float effortles..

$29.99 $39.99

Algebra - Bingo Bus™

Get on Board the Bingo Bus™ ! The well-loved game of BINGO is transformed into fun topics for Math. ..

$15.49 $17.99

Algebraic Thinking Games & Puzzles

Develop algebraic thinking and problem solving skills with these intriguing games and puzzles. Stude..

$19.99 $29.99

Amazing Animals

This book contains mazes of amazing animals, at different levels of difficulty. Enter the maze at th..

$1.99 $2.99

Amazing Buildings

This book contains mazes of famous buildings from around the world, at different levels of difficult..

$1.99 $2.99

Amphibians

Leopard Frog • Frog Eggs • Frog Tadpole- Late Gill Stage • Red spotted Newt • Salamander- Larval For..

$8.99 $9.50

Amusement Park Physics Game

Play the fast-paced game of Amusement Park Physics. Take a spin on the Tilt-a-Whirl, a hold on tight..

$11.99 $12.49

Ancient Life

Yellowstone • Brown Tide Algae • Stromatolite • Formminifera • Lichen- (3x) • Fungus - (1x0 • Ammoni..

$8.99 $9.50

Animals in Art 1: Art History CD DS

We find animals in great works of art from around the world to teach art concepts and learn about ar..

$3.99 $5.99

Animals in Art 2: Artists/Illustrator DS

Based on living artists who create in different media and styles, this CD-ROM looks at the way they ..

$3.99 $5.99

Aquarium

This strong tanks feature welded angle-iron frames, with a non-corrosive baked-on finish suitable fo..

$51.99 $377.99

Arithmetic is Fun Cross Puzzle- 2 Operation

This booklet contains arithmetic cross puzzles, which include the basic operations of addition and s..

$1.79 $2.49

Arithmetic is Fun Cross Puzzle- 4 Operation

This booklet contains arithmetic cross puzzles, which include the basic operations of addition, subt..

$1.79 $2.49

Art of Illusion CD

Twelve print images show works of art that fool the eye, including Relativity by M.C. Escher, The In..

$14.99 $19.99

Astronomy I - 6 Transparencies

Illustrate your point with this set of six overhead transparencies and one overlay. Topics include:..

$14.99 $29.99

Aurelia-The Life Cycle

Planula stage (120x) • Hydroid form (17x) • Budding polyp (17x) • constrictions in polyp (17x) • Str..

$8.99 $9.50

Automatic Burrettes (25ml) With Assembly and Container (Amber)

Automatic burette with burette tip assembly and amber storage container. The burette tip is attached..

$49.99 $69.99

Automatic Burrettes (25ml) With Assembly and Container (Clear)

When using the automatic barrette with tip assembly, you will find that the bead valve allows contro..

$49.99 $69.99

Balancing Board with Green cover - 13.75”

These balancing boards are very suitable for balancing exercises and rehabilitation of both children..

$29.99 $34.99

Ballistics Car

An essential for demonstrating that the forward velocity of a ball ejected vertically is the same as..

$19.99 $22.99

Basic Set 3-D Aerial Transparencies, Set/4 (Basic)

Basic Set includes images of rivers, valleys, cliffs, alluvial fans, folded mountains, and the erosi..

$7.99 $9.99

Basic Torso Discovery Pack

Constructed of durable laminated vinyl, this colorful 3-D Torso model is ideal for class demonstrati..

$69.99 $99.99

Basic Torso Discovery Pack

Constructed of durable laminated vinyl, this colorful 3-D Torso model is ideal for class demonstrati..

$77.99 $109.99

Basketball Toss Game Set

Increase your throwing accuracy with these new, fun toss games. Colorful vinyl mats are supported by..

$14.99 $15.99

Beautiful Butterfly

This booklet contains simple drawings with clearly defined lines, that the child may color with mark..

$1.29 $1.79

Binary Fission

Paramecia - living (10x) • Paramecium - living(100x) • Paramecium- stained (100x) • Fission Begins (..

$8.99 $9.50

Black Natural Bristles 51mm D. x 152mm L. x 430mm Tl., DZ

Cylinder and bottle brush with bristle. Available in black color. Measures 51mm diameter by 152mm le..

$14.99 $16.99

Black Steel, Size 0, 100/pk

Insect Pins, Black Steel, size 0, 100/pk - 38mm. Insect pins are perfect for mounts and displays! Th..

$8.99 $11.99