IsoPacs along with the MegaPac all feature the ClearSonic Lid System (roof) that helps reduce the amount of sound that would normally escape upwards. The Lid is especially helpful if you have a room with high, hard ceilings. IsoPacs are for applications where the lid (roof) is not necessary. These packages still feature SORBER absorption baffles to control the reflected sound. The IsoPacs are easy to get in and out of. The acrylic wraps around the front of the booth, while the SORBER panels wrap around the rear. Since SORBER panels don't actually connect to ClearSonic Panels, you can simply use one side of an S5-2 (two sections hinged together) as a "door". All 5 of these drum shield packages are offered with your choice of light grey and dark grey sorber panels.