Portable cribs or play yards have a few basic parts--the frame, the mattress pad and the carry sack. Other add-on accessories include a diaper-changing top, a bassinet top, toy mobile, diaper sacks and hood. Some portable cribs are even outfitted with vibration and sound, wheels for easy transport and the press of one button to easily fold it.
Stand the frame upright position and open the unit out like an umbrella, making sure to keep the center upright as well. Each of the four sides have top rails that are pulled up to snap the two-part bars into one straight bar. Once all the rails are snapped into place, the bottom is ready to be pushed all the way down to stand the portable crib up onto the floor.
If you were to push the center down before straightening each of the rail bars, these bars would not snap into place. The bars need extra room to pull up and into place, and when the bottom is in its folded position, there is enough room to pull the bars up and into its locking position.
The Mattress Pad
Once the portable crib is in its assembled position, you will notice the bottom is merely fabric covering the crib's legs. This is where the mattress pad fits. One side of the mattress pad is cushioned to give your baby a comfortable surface to rest and play on--this side will be up. The other side is the hard support that rests on the frame of the portable crib's legs. The mattress pad is the final piece that adds to the structural support.
The mattress pad is also used to hold together the frame when it is folded up and ready to be packed away. Most mattress pads have Velcro straps that hold the mattress pad closed around its frame. The unit is then placed inside its carrying bag and it's ready to go.