• Generalaire Humidifier Pad 990-13
• For Models 1042, 1042L, 1042LH, 709, 990, 1040, 1137 & SL16 Humidifiers
• Actual Size 12" x 9 3/4" x 1 3/8"
• Package of 2 

Note:

This  Water Panel or Humidifier or Evaporator Pad or Vapor Pad is made of expanded aluminum coated with a hydrophilic (affinity for water) material that absorbs and holds water flowing through the pad. As warm air flows across the pad this water evaporates and humidify the air.

The pad should be changed once per heating season as minerals in the water are trapped on the pad thus, restricting both water and air flow. Cleaning is not recommended since it removes the hydrophilic coating and reduce the performance of your humidifier.