Inserts will be back instock end of February. If you are in need of one urgently. You can purchase one direct from the IKEA website or collect in store.
https://www.ikea.com/gb/en/p/antilop-supporting-cushion-white-30449748/
Our cushion inserts are inflatable and provide a soft, comfortable support for your little one, simply add your desired cover to the insert! 
BPA free
21 cm height: 2 cm length: 26 cm