Slumberland Soho Mattress-Firm The Slumberland Soho Firm mattress has quality all stitched-up. Using a traditional 3-zone Bonnell (spring) support system made with tempered steel, this exceptional mattress offers improved support, reinforced at the perimeter with AdvancEdge, an element designed to maximise the sleep surface and provide a stable seating edge. With premium comfort layers including SelectQuilt foam for added conformance, this smooth top design is finished with a soft, stretch-knit sleep surface for enhanced breathability. With over 100 years of experience making mattresses, Slumberland’s Soho mattress is a great all-rounder from a trusted brand. Look forward to bed again with this quality Australian-made mattress.