This pack of Yocan Evolve Plus Coil Caps is meant for use with the Yocan Evolve Plus atomizers. The coils caps connect to the Yocan Evolve Plus atomizers via threaded connection. They prevent wax from leaking out of the atomizer (a common issue with wax pens) and generate better heating. The Evolve Plus coil caps lock in hot air as the heating element of the atomizers (sold separately) produce giant eNail-like rips.