Hi Phil,

Although the density of the latex used in the toppers is the same as the core products, because it is thinner it provides a softer feel than the thick core.

As far as the softer of the two toppers is concerned, the 7.5cm topper with the Fusion 1 will provide a softer sink feel than the 5cm topper accompanying the Fusion 3.

This is because as it is 50% thicker again than the 5cm one, it depresses slower providing that luxurious sink feel prior to reaching the support of the core.

I trust that this helps.

Kind Regards Gary