If you have a basic bag after 1day1bag,
You can buy this item when his cover is covered.
https://live.staticflickr.com/65535/48077294962_0409eeb059_z.jpg
If you want to use it alone,
You must buy a "D-Ring" or "Strap".
-Additional "D ring belt", can be used as 1. cover cover 2. notebook set
- After buying the "strap belt", it can be used as 1. cover cover 2. notebook cover 3. shoulder bag
https://live.staticflickr.com/65535/48077227653_2d186b60ba_z.jpg
● Front main bag size: 26.5 x 35.5cm (hidden zipper 26.5 cm)
● Back pouch size: 15x22cm / 15x28cm
● Small pencil pockets on both sides: 2.5x22cm two, 2.5x28cm two