question: opal satin polycarbonate diffuser.supplied with silicon gasket and screws in stainless steel.
Capitalize this past sentence correctly.
A: Opal satin polycarbonate diffuser.Supplied with silicon gasket and screws in stainless steel.

question: easy installation, operation and maintenance
Capitalize this past sentence correctly.
A: Easy installation, operation and maintenance

question: it has a relatively narrow channel 250 meters wide and 1400 meters long.
Capitalize this past sentence correctly.
A: It has a relatively narrow channel 250 meters wide and 1400 meters long.