Wax cart

"What is a 'Wax Cart'?" (Technical Explanation)
Ignoring the legal aspects, let's break it down purely from a hardware perspective:
Contents: Not liquid nicotine e-liquid, but solid or semi-solid cannabis resin concentrates (BHO, CO2 extracts or live resin), with THC content typically ranging from 60% to 90%, much higher than that of natural cannabis flower leaves.
Hardware interface: The majority adopt 510 standard threaded interface, which can be screwed onto the universal small battery rod.
The main difference from ordinary electronic cigarettes:
Power requirement is extremely low: The resistance of the atomizer core in the Wax cart is usually between 1.2Ω - 1.5Ω. The optimal power is only 3.3V - 3.8V (approximately 5W - 8W). If a high-power device (over 15W) is used incorrectly, the cotton core will burn out within one second and release highly toxic carcinogens.
Preheating requirements: Due to the viscous nature of the wax, it is usually necessary to "preheat the flame" for 1-2 seconds before suctioning. This melts the solid wax into a flowing liquid; otherwise, it is prone to dry burning.
Fatal health hazard (EVALI): In 2019, thousands of cases of "e-cigarette lung injury (EVALI)" broke out in the United States. The culprit was the vitamin E acetate added as a diluent in illegal Wax cart. This substance cannot be metabolized once inhaled into the lungs and will directly cause obliterative bronchiolitis (popcorn lung), which is irreversible and lifelong.
If you merely mistook "Wax cart" for "high-viscosity nicotine salt"...
In very rare cases, overseas there are also uses of "Wax" to describe thick e-liquid with a high VG (vegetable glycerin) ratio, but this term is extremely uncommon. If you are looking for high-concentration nicotine salt cartridges (similar to those of Vuse or Juul), then it is not called "Wax cart" at all. Instead, it is called "Pod" (cartridge) or "Nic Salt" (nicotine salt).