Features. Optic glass feeder is an eye-catching way to attract hummingbirds. Clear glass lets you monitor nectar levels; Features a red plastic base and top. 3 perches and 6 feeding stations invites multiple hummingbirds to feed. Easy to fill and clean with wide mouth twist-off base. Audubon Swirl Glass Hummingbird feeder lets you monitor nectar levels. Bright red plastic base and top. Holds 16 oz. of nectar