This cover includes 2 pieces: 1 frame cover and 1 seat cushion (reversible). It will only fit the IKEA Tomelilla low back armchair measuring 78cm at the back (legs not included) sold from 1994-2002. You have chosen the Tomelilla model that measures 78 cm high at the back.   To check you have chosen the correct size, measure lengths A and B according to the illustration. This will confirm if your armchair requires a Standard or Small size. Begin measuring length A 7 cm below the top of the chair. Standard size: A = Approximately 20 cm , B = Approximately 20 cm Small size: A = Approximately 12 cm , B = Approximately 16 cm Please note! If your model measures somewhere in-between (for example, A measures 12 cm and B measures 20 cm, or A measures 20 cm and B measures 16 cm), please select Standard size.