Amazon has the Rubbermaid LunchBlox Sandwich Kit, Green 1806231
For $5.51 as an add on item.
Modular containers snap together to save space and stay organized, and can be stacked to fit various lunch bag shapes and sizes
Blue Ice freezer packs snap directly to food containers, keeping lunch chilled when you’re on the go
Durable lunch box containers have a secure lid seal to prevent leaking
Kit Includes: 2 Snack Containers (.5 cup capacity), 1 Side Container (1.2 cup capacity), 1 Sandwich Container (2.6 cup capacity) and 1 Medium Blue Ice (Size: 4.81″ L x 5.625″ W x 5.25″ H when stacked)
Microwave, dishwasher and freezer safe, BPA-free