E3D Revo™ HeaterCore (24V and 12V Core) (40w)

• The HeaterCore secures onto a Revo-compatible cold side using a Revo HeaterCore spring (included). After it’s attached, just screw in a Revo Nozzle and you’re ready for simple, tool-free nozzle swaps that don’t need hot tightening.
• Heats up much faster than a typical heaterblock. It’s designed to be much safer, too – a positive temperature coefficient (PTC) means power reduces as it gets hotter, reducing hazards in the event of a thermal runaway.
• Compatible with many popular 3D printers such as Creality CR series and Ender series, Prusa, Anet, Biqu, Monoprice, and many more. 
• Learn everything you need to know about the Revo HeaterCore in E3D's blog.

Unsure on the voltage you need? E3D has a nice page to help you identify the voltage from your power supply: https://e3d-online.com/blogs/news/12v-vs-24v