At the moment, our mid-century replacement IKEA sofa legs come in 3 designs, 2 sizes (regular and tall) and 2 types of wood which are Beech & Cherry.
These legs go at a minimum quantity of 4, all pre-installed with an M8 bolt which works with these IKEA models generally: Karlstad, Klippan, Karlsfors, Klobo, Ektorp, Soderhamn, Solsta, Sandby, Härnösand, Stockholm, Sater, Ystad, Mellby.
For other models not listed here such as the Karlanda, Kivik or Nikkala, you might need a universal adaptor fixed onto your sofa first and then you'll be able to simply screw on our legs.
These adaptors can be found here: http://www.amazon.com/dp/B013RZFBVW?psc=1
If unsure, do drop us a message and we'll help you out :)