This mini crib mattress is strictly designed for baby's physical characteristics. It won't collapse, is firm which provides good support. The crib mattress meets the 16 CFR 1632 /1633 and 16 CFR 1241 Federal Flammability tests. Whether it's lying down or rolling on the mattress, there is no sound. So that can reduces tossing and turning, it can improve the quality of sleep. Safety Certifications: The mini crib mattress meets the 16 CFR 1632 /1633 and 16 CFR 1241 Federal Flammability tests Firm Support: This mini crib mattress is strictly designed for baby's physical characteristics. It won't collapse, is firm which provides good support High Quality Material: Made of a breathable fabric and filled with comfort foam No Sound: Whether it's lying down or rolling on the mattress, there is no sound. So that can reduces tossing and turning, it can improve the quality of sleep Dual-Sided: Our mini crib mattress are designed to be used on both sides and it is recommended that the mattress is flipped or rotated every 2-3 months to maximise performance Product Dimensions: 38“L x 24”W x 4"Th. Please measure your crib size before buying.