Ultimate Sleep Cal King 3" Latex Mattress Pad Topper 100% Natural Latex, Medium Soft Density Add a layer of springy comfort which is naturally hypoallergenic and anti-microbial Made from 100% pure Natural White Latex; Superior Orthopedic Support Made of pure "green" (natural) 4.75 lb density (16 - 18 IFD) latex The gain is a greater range of firmness/softness of the finished foam Each topper sports air ventilation perforation to help keep your topper fresh and dry