From Warhammer 40k - Lexicanum
Canoptek Sentinels are Necron constructs used to control the raw elemental energies of a Transcendent C'tan. The Sentinel draws from the C'tans own power to generate a force shield that helps shackle the C'tan to a Tesseract Vault.
- 1: Games Workshop
- 2: White Dwarf July 2013 - Necron Tesseract Vault