Borescope pro diesel engine kit 4 5mm probe sealey vs8200 the incredibly small probe diameters incorporated into this tool make it first choice for the diesel engine specialist where the tiny probe can be passed through most glow plug holes in the cylinder head this makes inspection of the internal bores fast and easy an optional side view probe with an even smaller diameter is also available for this tool the image is displayed on a crisp clear screen and can be shared using the av c