アクリロニトリルブタジエンゴムでしょう
akurironitorirubutajiengomudeshō

Noun
Desu Copula

Expresses probability in a polite manner ("probably…") of アクリロニトリルブタジエンゴム

1. Acrylonitrile butadiene rubber, likely.; It's probably acrylonitrile butadiene rubber.

Polite
Presumptive
Conjecture