Gordo Scientific makes the best carb caps on the market today. Located in Pine, Colorado. They have been making precision carb caps that have gained the attention of the most particular of connoisseurs all over the world. The Riptide Cross-current allows the user to reverse the direction of air flow by simply choosing to cover one inlet or the other. Made with premium borosilicate, these are a must have for even the pickiest of dabbers.