Ray-Ban 2140 Wayfarer - Beau Martin Williams - Americons
The glasses have a black frame and the lenses are not polarized, otherwise a small "p" would visible next to the Ray-Ban logo on the lens.
The Wayfarer is one of the most popular sunglasses frames, see more Wayfarer sightings in movies.
Reference: Ray-Ban RB 2140 Wayfarer - Color: Black (code 901)
In the same film we can see the other main character, played by Matt Funke, wear a pair of Persol 714 Steve McQueen sunglasses.