This is worth every cent and more - I have had mine for over 6 years now and it is still going strong.
Waterproof Sheet Protector
Keeps sheets dry throughout toilet training
100% water proof with non-slip backing
Fits over the bottom sheet to protect mattress
Protects sheet from moisture and staining
Absorbent Soft Quilted cotton/poly surface with tuck-in flaps
Bleachable, Machine Washable and Dryable Protector
Size: Approximately 75cm x 85cm