The Gyokucho No. 297 is a 180 mm dozuki, a Japanese back saw with a 0.3 mm blade and fine 25 TPI teeth, built for dovetails and small joinery.
A full-length metal back holds the thin blade straight to the tip, so it tracks a knife line through dovetails and tenon shoulders. It is at its best on dovetails in boards up to about 1/2 in thick, and it handles dry bamboo too. This is the basic dozuki we recommend for fine joinery. The S-297 replacement blade is sold here too.