The Pickonimbus 2000 is a reference to the Nimbus 2000 broomstick from the Harry Potter franchise.
This is the only pickaxe to have durability.
The pickaxe does not have a durability bar even though it breaks after 2,000 uses. Instead, the number of uses left is displayed in the lore.
A Pickonimbus 2000 can be repaired to full durability in an Anvil by placing a brand new unenchanted Pickonimbus in the first slot and the damaged one in the second slot. It will transfer over enchantments, but not reforges. However, it resets the Compact counter (but not the enchantment's level), making 4 the highest level attainable on a Pickonimbus 2000 that didn't already have a higher level before SkyBlock 0.19.1.
Unlike Drill Fuel, blocks mined by ▚ Mining Spread and abilities that break multiple blocks at once (such as Pickobulus) also remove durability from the Pickonimbus 2000.
It is not possible to auction a Pickonimbus 2000 below 2,000 durability, but they can still be traded.
In the SkyBlock 0.20.6 update, existing Pickonimbus 2000s that were at full durability were reduced to 2,000 durability, but ones that were between 2,001 and 4,999 durability kept their extra durability.
This is because Pickonimbuses at full durability do not have a pickonimbus_durability tag in their NBT data, and damaged ones were not modified.
This update also resulted in Pickonimbuses with more than 2,000 but less than 5,000 durability becoming auctionable.