Oval to 6" duct adapter HVAC

6" end outer diameter – 149.76 mm

Oval end inner dimensions – 65 mm x 129 mm

Depending on your climate you may not want to print this with PLA.

Made for Panasonic FV-0510VSL1 WhisperValue DC Ventilation Fan.

EDIT: included a 20 degree elbow as well.

Source: 
https://cad.onshape.com/documents/dd1cbacfc0fa91f35ec8cf5a/w/0c31ac7d6931545bf66fc40b/e/7298f45658385d3bd8a66b7f