An Acme Klein Bottle is a perfect gift for a mathematician, computer scientist, or troglodyte. In Germany, it's called a Kleinsche Flasche. A Klein Bottle makes a great math gift and an ideal present for a mathematician!

Origami Klein Bottles? Yep! Also, check out my Klein Bottle Slicing Machine

We made the world's largest glass Klein Bottle for the Kingbridge Centre!

Answer to my most commonly asked questions:

1) Yes, I am Cliff Stoll, and I make and sell Klein Bottles.

2) Yes, I regularly send these to countries around the world.

(As of 2020 mid-August several countries are unreachable by post: South Africa, Philipines, India and all of South America )

3) Yes, you can safely order from this website, and I will send your Klein bottle within 24 hours.

4) Yes, I pack each one very securely to survive the post; I guarantee safe, speedy delivery.

5) If you are unhappy with your Klein bottle, I will refund your money.

6) If this is a gift, I'll print "Happy Birthday" (or whatever you want) on the packing slip or the outside of the package. If you wish, I'll write your message on the bottle with a Sharpie pen.

7) No, I no longer do the hot glass work - I contract this out to professional glassblowing shops. I do everything else myself - from design to packing to writing the html on this website, with occasional help from my son Danny, my daughter Zoe, and my wife Pat.

8) Yes, you are welcome to visit if you are traveling to Northern California (San Francisco/Oakland/Berkeley) Call first - 510 654 3958

9) No, I cannot engrave these glass Klein bottles. The borosilicate glass laughs at laser beams and the compound curves defy X-Y tables..

10) Yes, there are many math jokes on this website, but despite that, I really do sell Klein bottles

11) Yes, my son Danny and I designed each of these bottles ourselves. Our designs are copyright © by Cliff Stoll

12) My website looks old-fashioned because it loads faster this way and (mainly) I'm too lazy to rewrite it. I last updated this page on Saturday morning, Sept 5, 2020, while enjoying a cup of Kona coffee.

13) Yes, that's me in the [ video / book / talk / college / bowling alley ]

-Cliff Stoll in Oakland (two blocks from Berkeley, 10 km east of San Francisco, and epsilon away from a boundary)

ARE YOU A STUDENT, AGE 12 TO 17? Do you like the kind of math humor that's on this website? Then consider one of the terrific summer math camps! Several that come to mind: the Hampshire Summer Studies in Math (in Amherst, Massachusetts during July & August... learn why the Yellow Pig endorses 17 varieties of Acme Klein bottles -- hcssim.org). Also, the MathILy program at Bryn Mawr (five weeks of maximum mathematical marvelousness) (www.mathily.org). I've also heard great things about Epsilon Camp in Utah (well, one of the Epsilon camp counselors visited, and she really impressed me!) There are dozens more camps-- see a list of these camps at www.ams.org/programs/students/emp-mathcamps ... feel free to ask me for opinions or comments about these various math camps. Also -- Math Circles are springing up around the world ... find out if there's one in your neighborhood: www.mathcircles.org/Wiki_ExistingMathCirclePrograms_view