The S-290 is the replacement blade for the Gyokucho Usuba No. 290, a 180 mm pull saw for fine crosscuts in wood, plywood and bamboo.
It has the same specs as the blade on the saw: 0.3 mm thick with crosscut teeth at a 1.5 mm pitch (16.9 TPI), a 0.51 mm kerf, and a curved tip that starts a cut in the middle of a flat panel. A metal back stiffens about three quarters of the length. When the teeth dull, fit a new blade and keep your handle.
Gyokucho saws are made in Miki, Hyogo, by Razorsaw Kogyo, which was set up in 1969 when it developed the replaceable-blade saw. Gyokucho Sangyo, its sales company since 1975, sells them.