Holowan Mechanicals (HM) was a subsidiary of Holowan Laboratories. The company was notable for manufacturing the IG-series assassin droids though it actually bought the blueprints from Phlut Design Systems after it declared bankruptcy following its takeover by the larger InterGalactic Banking Clan.
Holowan Mechanicals was responsible for manufacturing the IG-100 MagnaGuards, the deadly droid bodyguards of the feared Separatist leader General Grievous. Following the Clone Wars, the company went on to build the infamous IG-series assassin droids including IG-88, IG-72, IG-97 and the IG-110 Lightsaber Droid.
- The Movie Trilogy Sourcebook
- Galaxy Guide 10: Bounty Hunters
- Cynabar's Fantastic Technology: Droids
- The Essential Guide to Droids
- The Official Star Wars Fact File 4 (ASS1–2, IG-88 Assassin Droid)
- Star Wars: Revenge of the Sith: The Visual Dictionary
- The New Essential Guide to Droids
- Star Wars Roleplaying Game Saga Edition Core Rulebook
- Star Wars: The Clone Wars: The Visual Guide
- The Complete Star Wars Encyclopedia
- Scavenger's Guide to Droids
- Star Wars: Edge of the Empire Core Rulebook
- Star Wars: Age of Rebellion Core Rulebook
- Endless Vigil