Tough Box construction consists of the use of a Multi-Layer wood core (see below) and a composite/fiberglass sheath to create the ultimate resilience and snap for our freeskiing models. The sheath is wrapped around the wood core in the mid-body of the ski, increasing strength and screw retention. Many Vˆlkl freeskiing models also feature a carbon layer in the bottom of the ski that provides additional stability and durability.