Customizable size The cushion can be customized to fit your bed or sofa. Choose the customize option to specify exact dimensions for a tailored fit, delivering comfort and support where you need it. Premium materials The mattress extension cover is made from high-quality linen fabric that is breathable and soft to the touch. The insert is filled with an improved eco-friendly foam with high density and high elasticity, providing long-lasting comfort when leaning against the headboard. Fills bed seam gaps Designed to permanently address the gap along the bed seam and reduce the distance between the footboard and the bed. The cushion stays in place, helping to prevent gaps from reopening and improving overall stability. Wide compatibility and applications This durable bed gap filler offers comfort, support, and convenience. It can be used as a double bed bridge, as an armrest or headboard extension for wooden sofas, and to bridge the gap between the headboard, wall, and mattress. Use scenarios 1) In a double bed setup with a visible gap between the mattress and headboard, place the cushion to create a seamless sleeping surface. 2) On a wooden sofa, use the cushion as a comfortable armrest and back support. 3) Along the edge where the headboard meets the wall and mattress to fill the vertical gap and keep bedding in place.