Omni-gel

From Mass Effect Wiki

Omni-gel is a technological material that can be obtained by breaking down unwanted items, such as weapons, armor, and upgrades from the equipment screen. Doing so will usually give you 4 omni-gel per item. It is designed for use with omni-tools to do electronics or decryption work. Omni-gel can also be used to repair the Mako, though doing so requires the vehicle to be temporarily off-line.

Omni-gel is composed of common, reusable industrial plastics, ceramics, and light alloys kept in a semi-molten state. Being able to render non-essential upgrades and weapons into omni-gel allows them to remain useful while reducing weight.