Ribosome-associated vesicle
Ribosome-associated vesicles (RAVs), are novel sub-compartments of the rough endoplasmic reticulum, a membranous cellular network that is important for the synthesis and transport of proteins. RAVs have been observed via multiple imaging techniques and appear as discrete spherical vesicles that are associated with actively translated ribosomes.
Source: Wikipedia — Ribosome-associated vesicle (CC BY-SA 4.0)