1' panels fold accordion style every 2' for convenient storage. Rigid, 1 3/8'' cross-linked polyethylene foam. Touch fasteners on 2 short ends allow you to attach additional mats. Cross-Linked Polyethylene Outlasts non-cross-linked foams! Provides unsurpassed shock absorption, compression resistance, cushioning, and resiliency. Cell structure will not break down. Retains 100% compression even after 150,000 impacts. Heavy-duty, 18-oz. vinyl-coated nylon cover offers increased durability, particularly at stress points. Lighter-weight, 14-oz. vinyl-laminated cover resists tearing. Both covers are treated with antibacterial and anti-fungal additives, double-nylon stitched for strength, and can be cleaned with a diluted disinfectant. 18-oz. vinyl-coated nylon cover. SIZE: 4'x6'.