4PCS Square Foam Cube - Polyurethane Foam Block - Cut and Peel Foam for Tool Box

Use a Hair Dryer (Low Heat Setting): Lightly blow warm air (on low heat) over the foam for a few minutes, then let it sit undisturbed to expand naturally. Made from foam material, this toolbox foam insert is and -lasting, making it a great accessory for any DIY enthusiast or professional contractor.

eBay