10 things you might want to carry in your sling bag

1. Hand sanitizer

2. Tactical flashlight

3. Napkins

4. Portable charger and cable

5. Wallet

6. Eyeglass cloth

For wiping glasses

7. Sunscreen

For day trips

8. Water

A waterbottle might be a bit too big - there are plastic ones that can hold water and fold up when not full

9. A pocket book

For when you're bored

10. A notebook and pen

For inspiration