Sangheili Ranger
From Halopedia, the Halo wiki
Summary
Title for a form of special forces of the Covenant. The Elite Rangers - An all-volunteer force that conducts its operations in the deadliest battleground imaginable: The unforgiving vaccuum of space. Whether they joined for personal glory or ancestral duty, they each know that a gruesome end awaits them from even the most inconsequential of injuries. Normally deployed as an expeditionary force during limited naval engagements it is they who choose which craft are to be boarded and which destroyed. Experts in both zero-g combat and demolitions, they have been the bane of many a ship.
Combat
They dual-wield Plasma Rifles, signifying they are of relatively high rank. Their helmets completely encase their heads, protecting them from the vacuum of space. They are usually seen travelling in small groups of 2-3. They are curious, as they seem to be gifted with symbols of respected elite rank, but have the blue armour of the Minor Elite, the lowest of the elite forces. They can pose a good challenge and are seen on Cairo Station, Delta Halo, Regret and Gravemind.
In Halo: The Fall of Reach, there were Ranger Jackals as well, present at The Battle of Reach. It seems that by the time of The First Battle of Earth, the Ranger Jackals have been replaced in combat by the Drones, which are already suited for space and are much more versatile in aiding the Ranger Elites.