Kellymarie, thank you for asking. Let's get the information you need.
We recommend exhausting the dryer to the outside. If you are referring to the exhaust duct, its diameter would be 4 inches (10.2 cm).
For more details, please refer to pages 18-19 of your user manual, specifically the "Ducting Requirements and Exhausting Requirements" section.
Manual
https://downloadcenter.samsung.com/content/UM/202312/20231228084543614/OID64579_IB_DV7500C_EN_231222.pdf
Should you need more assistance, please feel free to get back to us via the following options:
1. Facebook Messenger: http://m.me/Samsungsupport
2. Twitter: https://twitter.com/messages/compose?recipient_id=18768513
3. Samsung Community: https://us.community.Samsung.com/t5/Samsung-Community/ct-p/us
When you message us, please provide us with this reference number (1148964065) to help our team pull up your information.
Have a great day.
^Camille