"EXT" wrote in message

This model seems to be a modified angle grinder, I have seen another that
was built like a portable circular saw.

Also what happens if one accidentally twists the saw in the work and binds
the blades together. It would seem to be easy with the long motor/handle
and lack of guide plate. The blades are rotating in opposite directions.
The teeth will grind together creating who knows what shrapnel.

I think that was one of the benefits, shrapnel free or nearly so. It was
designed to be safer than a single blade saw.