Horizon RTG 'Lite' shipping boxes 20" long x 8" wide x 16" tall RTG (Ready to Go) filters are already glued in place saving time and mess New updated stronger cardboard Handles and cable ties are included; Dividers are not included Returned items may be subject to a 20% restocking fee Stronger bottom design than the Original, 2" longer, and .55 lbs. lighter (Weight 1.2 lbs.). Boxes are RTG Ready to Go, there is no need to go through the messy process of gluing the filters in. If 3 or 4 boxes are cable-tied, or taped together, the middle boxes will still have plenty of ventilation because they are tall with plenty of ventilation at the top. The heat rises and escapes. Another advantage of Horizon 'Lite' boxes is their length and height, which is good for adult birds with long tail feathers that need extra length. Their roominess also allows two smaller birds to be shipped together using a divider. These Horizon boxes are well designed with plenty of ventilation and room for large adult birds. Returned items may be subject to a 20% restocking fee.