COPALUM connectors use a special crimping system that creates a cold weld between the copper and aluminum wire, and is considered a permanent, maintenance-free repair. However, there may not be sufficient length of wires in enclosures to permit a special crimping tool to be used, and the resulting connections are sometimes too large to install in existing enclosures due to limited space (or "box fill"). Installing an enclosure extender for unfinished surfaces, replacing the enclosure with a larger one or installing an additional adjacent enclosure can be done to increase the available space. Also, COPALUM connectors are costly to install, require special tools that cannot simply be purchased and electricians certified to use them by the manufacturer, and it can sometimes be very difficult to find local electricians certified to install these connectors.