This Trundle bed may be used for your pet who likes to burrow or cuddle, and may be used bunched up as a nest, layer out like a tunnel, or stretched flat like a mat.This Trundle style bed when folded up in Cup Format measures 15 inches in diameter. When in sleeping bag format the trundle measures 24 inches long. Laid flat, fully extended, the trundle measures 24 inches by 44 inches.