Ester-pattern armored frigate
From Halopedia, the Halo wiki
The Covenant CAR-class is a type of ship mentioned in Transmissions, a type of promotion for the then new game, Halo: Combat Evolved. The transmissions are directly linked to the Cortana Letters and like the Cortana Letters aren't really considered Canon unless specifically mentioned in later Halo Canon works.
Nothing is really known about the dimensions of the ships, in fact the only thing ever mentioned about the ships are the following:
• CAR Contrition (DE H c-5)
- SCS Hermes II - The UNSC ship that received the transmission
- RECEIVED (trans) 04.14.6.1835
- via x-process 375.2.686.0632091
- (process owner GA - AI - Class II)
Through war we will teach your heresy.
Through battle we will teach your frailty.
Through death we will teach your fate.
• CAR Penance (DE H c-4: OB)
- ESP 8 Reach -- The UNSC ship that received the transmission
- RECEIVED 04.15.6.1428
- via p-process 34022.1.8.230390
- (process owner Pr Govern via Reach PSN
- node 21)
You live without discipline and will die without honor.