"four main components" is correct and usable in written English.
Example: The research paper outlined four main components of the study: methodology, findings, analysis, and conclusion.
I believe that our narrative should have four main components.
The K.& R. industry has four main components: K.& R. consultancies, insurance companies, corporations and governments.
BIPV systems have four main components: facades, glazing, pitched roofs, and flat roofs.
Earlier, the egg had been injected with bromodeoxyuridine (BrdU), a compound whose structure resembles that of thymidine, one of the four main components of DNA, and which is incorporated into newly-synthesized DNA.
Cisco's Security Intelligence Operations product has four main components.
This model consists of a combination of the four main components described above (Figure 1).
Lifelong learning models have four main components, i.e., knowledge representation, extraction, transfer, and maintenance/retention.
Fuzzy logic system consists of four main components: fuzzifier, rules, inference engine and defuzzifier.
The present review focuses on one of the four main components of basic fitness, strength.
The system is composed of four main components: Supervision, Slow Control, Fast Control and Data Acquisition.
Nick-named "the goat's head", its four main components started life as 924kg of aluminium, provided by Thyssen-Krup.
