This is a replacement air bladder cell for the Drive Medical 14209DPM alternating pressure mattress. This air bladder is available with or without laser holes. Both types of air bladders are necessary for the alternating pressure mattress to work properly. The cells with laser holes make up the middle 9 cells of this mattress, and they let the small amount of air necessary to alternate the mattress's pressure. The bladder cells without laser holes do not release any air, and make up the other 11 cells on the alternating pressure mattress. Each air bladder cell has an 8" height.