"of different size" is correct and usable in written English.
You can use it to describe objects that have variations in their size. For example: "The store had a selection of t-shirts of different size."
They used electrophoresis to separate nanodiamonds that were of different size and functionalized differently.
Bivariate and multivariate analyses revealed significant differences across hospitals of different size and accreditation status [ 9].
However, there were differences in the distributions of different size classes of Daphnia (Fig. 3).
These differences are also observed in the amount of labor allocated to plants of different size.
A difference in tumour killing efficacy was observed between the responses of tumours of different size.
Leaf-cutter ants, for example, come in a wide range of sizes, and those of different size have different jobs.
The council proposed several options for changes, including printing bills of different size and changing the texture by adding embossed dots or foil.
Studied micro/nano carbon materials consist of different size particles.
a Neurons of different size, surrounded by SGCs, were found.
a) Remote sensing sample units of different size.
(a) Micro-Raman spectra of different size Si NCs.
