Abh mod/Phaser Lance
The Phaser Lance was introduced in version 0.4.4. It's designed to breach shield and do moderate damage to armor. It's firing rate was designed to fire when the shields come backup. It's also designed to just pierce an unarmored target but not completely saw it in half.
It requires a technology level 2 control room. And since it's firing range is just beyond standard sensor range it requires a sensor room part. As a fixed weapon it requires its target to be right in front of it.
Cosmoteer 0.12.6 to 0.12.9 or earlier had a building mirror bug which prevented the weapon from shooting. This occurs when it is copied, mirrored and placed. If it is a savegame, reloading will fix the issue. New introduced effects handling in 0.12 also caused crashes with beam related effects. The issues are supposed to be fixed with Cosmoteer 0.12.10. The part's code was fixed in mod version 0.4.5 when the causes where finally identified.