The phrase "are either small" is correct and usable in written English.
It can be used when discussing options or categories that can be classified as small among other possibilities.
Example: "The items in the box are either small or large, depending on the size you need."
Alternatives: "are either tiny" or "are either little".
Burritos are either small (£5.25) or regular (£6.35).
Companies are either small family affairs or sclerotic behemoths.
Their slitlike nostrils can be closed underwater, and externally the ears are either small or entirely absent.
Males that are either small or large tend to display less aggression than those that are medium-size, according to the research, published in The American Naturalist.
Countries that are more developed rely heavily on exports of high-value products that are either small, like computer chips, or that require practically no shipping, like banking and insurance services.
But many state-owned enterprises that are not listed on exchanges have not issued shares because they are either small or, in many cases, virtually bankrupt -- making them unattractive to investors.
Most current reactor benchmark problems are either small-scale or involve spatial homogenization (pin cell or full-assembly) for diffusion codes; therefore, new whole-core benchmark problems must be designed in order to validate whole-core transport methods.
Other databases are either smaller in size, or as in the case of MAPPER, binding models are not available to the public (Voichita D. Marinescu, personal communication).
The majority of the targeted therapies are either small-molecule drugs that act on targets inside the cell (usually protein tyrosine kinases) or monoclonal antibodies directed against tumour-specific proteins on the cell surface [ 54].
All therapeutic studies in NMO have been either small, retrospective case series or uncontrolled prospective studies.
Lung cancers are often defined as being either small cell lung cancer or non-small cell lung cancer.
