Japanese Backed Tenon Saw
This looks like a classic 12 long Western-style joint cutting tenon saw. It is that, but with a critical difference - it has precision diamond cut Japanese pattern teeth. Depth of cut is 3". The body of the saw is .025" and the kerf 0.035". It is designed to cut on the push stroke. Must be used to be appreciated. It's an extremely productive tool. Made in Japan.