The Original STJ Precision Seal

The Original STJ Precision Seal

The injection-molded STJ Precision Seal is unique. Besides fitting PumpToy's large cylinders, it brings a variety of advantages to the simple and inexpensive Sun Tea Jar pump. With this seal, you can have a pump that is as effective and more comfortable than any standard two-stage cylinder, for a total investment of LESS THAN $40.00! PumpToys also makes an STJ Conversion Kit that will allow you to convert a Sun tea jar to a pump in one minute.

To learn how to make a Sun Tea Jar into a basic pump cylinder for less than $10, look at the Making an STJ Pump article in our library.

The STJ Precision Seal is used by beginners, because it makes the STJ practical, and it makes pumping easy and comfortable. But it's widely used by serious volume pumpers like this one. This is a legitimate photo- the size has not been distorted in any way. How big is he? You can use the seal as a reference for size... that seal is 5" wide!

Features of the STJ Precision Seal:

  • It's very comfortable, made of a soft gel-like plastic. NO hot-spots!
  • The seal is positive and trouble-free.
  • The entry is wide and funnel-shaped, eliminating the "pubic bulge" problem.
  • The opening reduces to 2-3/4", making your STJ into a two-stage!
  • Circulation is improved by better entry pressure distribution; You pump larger and faster!
  • The effects are terrific! Your pumped shape is more natural, necking at the top, and swinging!
  • The seal is left in place when you remove the cylinder- you get the full 4" opening to exit!
  • The seal is elastic, and is removed by simply stretching it over your pumped package!

This seal will fit the common STJ, and all PumpToy's combination cylinders- the ASTJ, the LongJohnny, and the BullMaster. It will also fit other straight-rim cylinders where the rim is 1/4" or less in thickness, with openings from 3-3/4" to 4". If you have questions about fitting- please inquire before ordering! Please note that petrochemical based lubricants are not compatible with Precision seals, and are also damaging to acrylic cylinders. We recommend only GLYDE, a natural vegetable-based lube designed specifically for pumping.

Vinyl Precision Seal
Part # STJ - The Original STJ Precision Seal    $30.00
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International customers, see our International Shipping Page for details about delivery to your country.