CHEERYMAGIC Wet Bag, Baby Cloth Nappy Wet Bags Waterproof Wet Dry Bag Outdoor Organiser Bag for Baby Items 2 Zipper Pockets Washable Travel Dry Wet Bag for Beach Pool Daycare Gym A4-CSNBD (Blue)

I used this to make a period kit for my daughter to keep in her school bag in case she comes on at school and it's a good size for that. It fits a pair of period pants, spare knickers, a couple pads, and a small pack of intimate wipes comfortably. It is only one pocket though so no means of separating wet and dry - I had to add in a ziplock bag for dirties.