This Hemera heatsink has a revised design to add compatibility with Revo Nozzles and a Revo HeaterCore. A milled lip at the bottom of the sink is designed to receive a Revo HeaterCore spring, and an extended hole allows you to screw in a Revo Nozzle of your choice so you can change nozzles without tools or hot tightening! - Compatible with 1.75mm filaments - Updated heatsink design - compatible with Revo HeaterCore and Revo Nozzles (sold separately) - Prevent part warping with specially designed fins direct air up and away from your 3D print to prevent part warping - No tools or hot tightening needed when changing nozzles – Revo Nozzles make it easy Please note: - This sink retains full compatibility with the Hemera HeatBreak, V6, Volcano, and SuperVolcano HeaterBlocks.