When you want to attach decor or other objects to the stage decks you can use the assembly insert, slide this insert in the profile and connect your object or decor to the stage deck with an M10 bolt. Easily slides into the profile of the Deck750 4x T-Bolt M10 8x M10 washer 4x M10 spring washer 4x Nut M10 Galvanized steel design Made in Europe