はん閉鎖 へいさ しきリブリーザーでしょう
han'e isa shiki riburiizādeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of 半閉鎖式リブリーザー

1. Probably a semi-closed circuit rebreather.

Polite
Presumptive
Conjecture