Mattress Cover Allergy Relief Twin size 39 x75 x9 Zippered Exercise Balls Hinged Elbow is designed to Strengthen muscles Hinged Elbow is designed to prevent hyperextension of the elbow * X cross hook & loop locking straps help restrict range of motion * Medial and lateral hinges provide a hyperextension stop at 0¯ * Measure around elbow joint with arm extended * Large 12 13Û * USB charging s sleep and allergy relief * All of our covers are laboratory tested and efficient against dust allergens and pet dander * Zippered Mattress Cover * Twin 39 x75 x9 * Six gauge vinyl * Heavy Duty and durable * One cover per package * 100% Waterproof * Fire retardent * Notice to California Consumers: WARNING: This product contains chemicals known to the State of California to cause cancer and birth defects or other reproductive harm * Our allergy relief bedding is designed specifically to prevent dust allergens from becoming airborne * The membrane free tight weave construction prevents dust allergens and pet dander from becoming airborne * No membrane means the most comfortable and cool night