The XS Series under the iMattress brand of King Koil is a collection of hybrid mattresses. Each of the four models in this series features a pocket coil innerspring support unit with foam encasement, iFusion gel memory foam, various firmnesses of Perfect Contour Foam, and a 4-way stretch jacquard knit cover. All these are in the iXS1, the basic model.
Each of the other models adds other components, such as Super Soft Foam Wave Foam, High Performance Foam (various weights), Enhanced Visco Plus, and Gel Response Latex. Heights of the models range from 11½ to about 14½ inches. The comfort level of iXS7 is Plush, and the other three are Medium Plush.
The iFusion foam, as described in the review of the iMattress G Series, is King Koil's formulation of ventilated gel-infused memory foam, combining the conformability of memory foam, the added support of gel, and the cooling of gel and airflow. iFusion is the top layer of each XS Series mattress.
All of the iXS models except the iXS7 have a layer of High Performance Foam. Excactly what this material is and does is not detailed in model descriptions, but in the iXS3 and iXS5 this is labelled Super Soft High Performance Foam. Lying as it does beneath the iFusion, it presumably adds support.
The Perfect Contour Foam is Cushion Firm in the iXS1, Super Soft in the iXS3, and Enhanced Ultra Soft in the iXS5 and iXS7. In the cutaway diagrams this foam has a textured surface, which means this accounts for the contouring, similar to the effect of convoluted foam but on a finer scale. The texturing also allows for more air circulation.
King Koil calls the encased pocket coil system Contour Luxury Plus. These are individually wrapped 13¾-gauge pocket coils with a coil count of 640 in a queen-size mattress. Pocket coils' independent response allows them to conform to sleepers' body contours to reduce pressure on large body parts (like the hips) and support the smaller ones (like the lumbar). The height of the coils is not given, but from the cutaway views they appear to be about 8" tall.
Surrounding the innerspring is the 4" wide Excellent Edge Foam Encasement to protect the coils and support the sleeping surface.
To the features of the iXS1, the iXS2 adds a layer of Super Soft Foam Wave Foam. The wave pattern of this foam enhances airflow through the mattress, which not only ventilates the interior, but also reduces motion transfer. This Wave Foam is also found in the iXS7.
Instead of Wave Foam, the iXS5 adds Enhanced Visco Plus, another formulation of open-cell memory foam, but without the gel. iXS7 has a layer of Advanced Visco Plus.
King Koil calls the iXS7 "the elite hybrid mattress." This could be called a "double hybrid." To the iFusion gel memory foam, this model adds King Koil's Gel Response Latex. Gel Response Latex is described as "breathable latex with gel beads." This combination of gel-infused latex and gel-infused memory foam is credited with this mattress's pressure relief.
The top panels of the covers of the iMattress XS Series models are made of a jacquard knit fabric with four-way stretch. The sides of the mattress are covered with mesh to facilitate ventilation for cooling and freshness.
King Koil's foundation is made from natural wood by Amish crafters. It is upholstered with a dark fabric compatible with the mattress. These mattesses are also adjustable bed and platform bed compatible.
All iMattress models, including the hybrid XS Series, are covered by King Koil's 10-year non-prorated limited warranty. They also have a 120-night sleep trial period.
King Koil iMattress Hybrid Series (2015)
King Koil, 7501 South Quincy St. Suite 130, Willowbrook, IL 60527, USA, 1-800-525-8331
Hybrid - memory foam and coils
Encased pocket coil innerspring with foam comfort layers, including gel memory foam.
Jacquard 4-way stretch knit
11.5 to about 14.5 inches
Slatted base, platform bed, or adjustable bed
Gel latex, gel memory foam, pocket coils
10-year non-prorated warranty
Keep in sanitary condition, and provide proper foundation