20/20

20/20 is popular shorthand for a wand, staff or focus item that gives the wielder a 20% chance of half Activation Time and a 20% chance of half Recharge for spells of a certain attribute.

The shorthand is also used for axes, swords, hammers, bows, scythes, spears, and daggers to mean having a sundering mod of 20% armor penetration on a 20% chance.