The ProAire 17" Hef-T-Block mounting block is a white heavy duty mounting base used on rooftops, ground applications, and other instances where you need to raise the unit above surface level. The sliding rail design allows for quick and easy attachment to equipment mounting feet. Works with single-zone and multi-zone mini split condensers, or most other residential condensers. 2 blocks per pack. Comes complete with mounting hardware and end caps.