From HoNwiki

Void Talisman
Cost
1,500
Stats
+7 to all stats
Modifier
None
Location
Relics
Dota Counterpart
Ghost Scepter

On Use Effect

Makes you immune to physical attacks and abilities for 4 seconds but reduces your magic armor by 5.5 and disarms your hero. 25 second cooldown.

The More you Know

This item can be activated during a channel without out breaking it.