The DEWALT DWST88801 TSTAK Foam Insert is an auxiliary product to the successful TSTAK system items. These removeable foam blocks allow user to easily customize for the needs of various power tool/equipment. These are constructed with strong and rigid - but lightweight - material that keeps equipment safe and protected. This gives flexibility and ability for multi-use customization to the end user. Fits DWST17808, DWST17807, DWST17805.