This nozzle only works with the HardCore Print Core Upgrade for the Ultimaker 3 and Ultimaker S5.
The tip of this nozzle is made of either clear sapphire or ruby (depending on the size and manufacture date). These materials have equal hardness and only differ in color. On a non-linear scale of hardness from 0 – 10, where brass has a hardness of 3-4, and steel has a hardness of 5 and up, the EVERLAST tip has a hardness of 9. Diamond is 10.