Hello,
Many thanks for your email, Unfortunately it is not that simple as the cassette would change the size of the blind and also the bracket type etc. it is not something that can be easily added to an order already received, It would be you would need to contact us with your order details and the blinds would need to be returned back to us at your own cost for us to rework to fit into a cassette and provide a cassette also,
If yo would like to proceed with this please email use your order details and blind size you are wanting to add a cassette too to [email protected]
Kind regards