evo.com | Outdoor Research Day Packs > One pack for the commute, the classroom, and the after-work hike. The Outdoor Research Heyday 20L Pack uses durable, water-resistant materials with a padded laptop sleeve, an organizer panel, and ergonomic EVA foam shoulder straps, plus a blinkie clip for a bike light on early morning rides. Ergonomic EVA Foam Shoulder Straps Blinkie Clip Light Attachment Point for Nighttime Visibility Shell 600D 100% Polyester Internal Laptop Sleeve and Organizer Panel 17.8 cm x 27.9 cm x 43.2 cm / 7 in x 11 in x 17 in | Outdoor Research Heyday 20L Pack 2027 - 20L in Gray | Polyester