Get a great night's sleep with the LUCID 4-Inch Gel Memory Foam Mattress Topper. This mattress features a gel memory foam construction that is ventilated to increase airflow and draw excess heat away from your body as you sleep.Plush firmness levelGel memory foamMattress topper1.9 to 2 - pound densityAntimicrobial4-inch thicknessResistant to dust mitesNever needs turningFoam is CertiPUR-US certifiedDimensions:California king: 4 inches high x 71 inches wide x 83 inches longFull: 4 inches high x 52.5 inches wide x 74 inches longKing: 4 inches high x 75 inches wide x 79 inches longQueen: 4 inches high x 59 inches wide x 79 inches longTwin: 4 inches high x 37.5 inches wide x 74 inches longTwin XL: 4 inches high x 37.5 inches wide x 79 inches longMemory Foam Tips:Arrives tightly packed in portable box for customer convenience.Remove from packaging within 72 hours to maximize expansion.You can sleep on it the same night it is unwrapped， however allow 48 hours to fully return to its original shape.Vacuum sealing sometimes traps odors. After unwrapping， air for a few hours to eliminate trapped odors.Due to machine-cutting manufacturing processes， there may be slight variances in the dimensions of this product.Due to the nature of Memory Foam the firmness level of similar products may produce different firmness resultsOnce opened this product is non-returnable.