End caps for round bars are packaged with our tower systems. If you are purchasing the bars as an individual order then you will need to purchase the end Caps separately.
There are two sizes of end caps, for 48 - 78" bars you need part number 8007026 that you can purchase here
If you have 86" bars you'll need part number 8880159 that you can purchase here
For more help contact us here, or by phone at 888-925-4621 during business hours