The Invacare Matrx PB Back Heavy-Duty Cover fits over an Invacare Matrx PB Heavy-Duty Back for increased user comfort and support. Built-in foam combined with the moisture-resistant and breathable cover help create a more comfortable environment for the user. For Quotes and Orders, please contact Matrx Seating & Positioning Customer Service at -1-888-433-6818 or visit www.motionconcepts.com for more product information.