Processes to produce poly alpha-olefin trimer and apparatus therefor

A composition, comprising:

• a plurality of poly-alpha olefins (PAOs), wherein the plurality of PAOs comprise;
• about 80 weight percent (wt %) or more of PAO trimers based on a total amount of PAO dimer, PAO trimer, PAO tetramer, and higher oligomers, wherein the composition comprises a kinematic viscosity @ 100° C. of about 4.5 cSt or less, wherein the PAOs are derived from an unsaturated poly alpha-olefin product comprising:
• greater than or equal to about 80 mol % vinylidenes, based on total moles of vinyls, vinylidenes, di-substituted vinylenes, and tri-substituted vinylenes contained therein;
• 0.1 mol % to 3.5 mol % of tri-substituted vinylenes;
• 3.0 mol % or less of di-substituted vinylenes;
• 3.0 mol % or less of vinyl groups;
• based on total moles of vinylidenes, tri-substituted vinylenes, di-substituted vinylenes, and vinyls contained therein;
• and
• having an Mn of less than 5000 g/mol as determined by 1H NMR.