Handmade Glass Klein Bottle

This elegantly curved glass Klein bottle will intrigue and delight any mathematician, physicist, or science buff. Like a Möbius strip, this Klein bottle has only one side. In addition, a Klein bottle has no edge - the connection from "inside" to "outside" is smooth, and the bottle has no lip. To a mathematician, this is zero-volume because it doesn't divide the universe into two parts. Despite this mathematical property, it's possible to fill it with water, although I don't recommend it, since it's difficult to dry (you can't get a cloth "inside") Each Klein bottle is hand blown from clear glass, so the exact shape and dimensions may vary slightly. Along with the glass Klein bottle, I include entertaining and (possibly) educational documentation, and a removable calibration decal.

• Ideal gift for a math or physics student, scientist, or computer programmer. Does not work as mousetrap.
• From Cliff Stoll, the Klein bottle guy - made from quality, low expansion borosilicate glass - microwave safe. Clear, non-colored, transparent glass.
• Zero volume, one-sided, nonorientable, 3-dimensional, unbounded, locally Euclidean
• About 8" tall, 4" diameter (20x10cm), weighs about 8oz (230g), ∇·B=0 and ∇×E=−dB/dt
• Rustproof, Batteries not needed, Riemannian, baryonic, satisfies Gauss-Bonnet theorem, free of any magnetic monopoles.