The 7 cm extension is ideal for homes with wider door openings or staircases it is compatible with the safety 1st simply close extra tall gate which fits opening widths of 73 to 80 cm when used with the 7 cm extensions this gate covers a maximum opening of up to 94 cm wide carefully measure the width of the opening before ordering extensions features extension kit adds an additional 7 cm to the width of the gate only compatible with safety 1st simply auto and easy close pressure fit gate