Figure 5
From: Imaging of underground cavities with cosmic-ray muons from observations at Mt. Echia (Naples)

Left: Sketch of the aluminium shell of a detection plane, consisting in 64 scintillator bars and the Front-End Electronics. Right: Sketch of the muon telescope, consisting of a vertical sequence of three modules, mounted horizontally on a support (not shown) and evenly spaced in the vertical direction (z-axis).