Hi Glen,
 
Thank you for your enquiry.
 
A Fusion 4 can be used on a slatted base with the following proviso :-
 
We would advocate placing thin (3-5mm) MDF over the slats. This will provide the mattress with a uniform surface upon which to sit and prevent ridging occurring as a result of the mattress dipping into the gaps between the slats, and being felt when the mattress is turned.
 
We trust this helps, but if you require any further advice or guidance, please call our office on 0161 437 4419 and speak with one of our advisors.
 
Kind regards.