こう性能 せいのう爆薬 ばくやくでしょう
kōseinō baku yakudeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 高性能爆薬

1. High-performance explosive, likely.; Probably a high-performance explosive.

Polite
Presumptive
Conjecture