The 28 cm extension is ideal for homes with wider door openings or staircases it is compatible with safety 1st simply easy and auto close pressure fit gates which fit opening widths of 73 to 80 cm these gates can also be used with 7 and 28 cm extensions to cover a maximum opening of up to 136 cm carefully measure the width of the opening before ordering extensions features extension kit adds an additional 28 cm to the width of the gate only compatible with safety 1st simply auto and easy