The NFL made an exception to its rules on tinted helmet shields after announcing a four-year partnership with Oakley on Tuesday.

As part of the deal, Oakley’s Prizm Clear shield will be available for players to wear for this upcoming season. The Prizm Clear has only a slight color tint.

The NFL rulebook says tinted eye shields may only be worn if the league approves a request after being supplied medical documentation. However, the Prizm Clear shield is an approved exception.

Oakley has produced helmet shields for over 20 years. The brand signed 2018 NFL MVP Patrick Mahomes II earlier this year in its first ever endorsement deal with an NFL player.