EntityLivingEquipmentChangeEvent is fired when the Equipment of a Entity changes. This also includes entities joining the World, as well as being cloned.

slot contains the affected IEntityEquipmentSlot.

item contains the IItemStack that is equipped now.

olditem contains the IItemStack that was equipped before the EquipmentChange happend.

You will need to cast the event in the function header as this class:
crafttweaker.event.EntityLivingEquipmentChangeEvent
You can, of course, also import the class before and use that name then.

EntityLivingEquipmentChangeEvent implements the following interfaces and are able to call all of their methods/getters/setters as well:

• ILivingEvent

The following information can be retrieved from the event:

ZenGetter	ZenSetter	Type
ZenGetter newItem	ZenSetter ​	Type IItemStack
ZenGetter oldItem	ZenSetter ​	Type IItemStack
ZenGetter slot	ZenSetter ​	Type IEntityEquipmentSlot

The following information can be retrieved/set during the event:

ZenGetter	ZenSetter	Type
ZenGetter entityLivingBase	ZenSetter ​	Type IEntityLivingBase