Lengths of 'foam' material (Sharmans Cross B91)

2 lengths of some kind of foam material approx. 5' x 20" (1.5 m x 50 cm) and a smaller piece approx. 2' 6" x 18". The photo showing the side of the foam there's a 3' ruler by the bottom of the rolls to give an idea of size. I'm not sure of their condition or what they were used for.