The Personal Safe is a mechanical storage unit in IndustrialCraft 2 that can only be opened by the first player that uses it, and server OPs. The Safe is primarily used in multiplayer in order to prevent griefers from taking items. The Personal Safe has a 54 slot capacity, equal to a double Chest.
The Personal Safe does not need any form of power, and is a relatively affordable way to protect valuable items from griefers. It will not work in automation systems, as it will not connect with anything that can affect its inventory. The Personal Safe is also effectively indestructible. An empty Safe can be picked up by its owner or a server OP by using a Wrench on it; a full Safe cannot be moved by anything.