Mechanic have access to the following alternate class features.
You construct an experimental prototype, a unique item that
represents your research and development into a specific new
type of technology. Your experimental prototype can take one
of two forms: an armor or a weapon. You must choose one of
these forms upon taking your first level of mechanic, and once
this choice is made, it can’t be changed.
If your experimental prototype is ever destroyed or lost, you retain its schematics in your custom rig and can rebuild a version of it for free using your custom rig after 24 hours of uninterrupted work. This free version is of an item level no greater than your mechanic level – 2 (minimum 1st level). You can take a single 8-hour rest during each 24 hours spent working, but any interruption greater than a moment of conversation requires you to add 12 hours to the time required to rebuild your experimental prototype. In addition, every time you gain a mechanic level, you can rebuild your experimental prototype with the same amount of work, allowing you to change the type of armor or weapon you chose as a basis for your experimental prototype (selecting an item of the same type with an item level no higher than the item level of your previous prototype).
For more info about Experimental Armor Prototype and Experimental Weapon Prototype.
Experimental prototype replaces the artificial intelligence (AI) class feature.