The 122-24 is the medium-tooth replacement blade for the Silky Gomboy 240 (121-24), the folding pruning saw for limbing, trail work and dry, hard timber.
It's the same blade the saw comes with: 240 mm (9.45 in), 1.3 mm thick with a 1.4 mm kerf, chrome plated and taper ground, with non-set, impulse-hardened teeth at 10 per 30 mm (8.5 TPI). It swaps on the saw's pivot screw, so you keep your handle.
Katsuji Miyawaki founded Silky in 1919 in Kishi, Japan, under the brand Tamakitsune, and all of its saws took the Silky name in 1983. The company is now headed by Uichi Miyawaki, and its saws are made in Ono, Japan.