Pulled this description from another ebay listing of this same size:

Product Features

• One of the most popular bass wheels developed for professional use
• 6" ball-bearing, pneumatic wheels with heavy duty air valve for easy-to-roll cushioned support
• Interchangeable custom spindles and stainless steel forked frame
• A 2 sided bicycle style brace
• Made in USA

• One Genuine Xeros Upright  Bass Transport Wheel 3/8" Shaft 

I purchased this item at a recent estate sale.  I had to do some research to figure out what it was. Because it was on a shelf in a closet with the original receipt and clearly had never been used, I was intrigued enough to buy. I have taken numerous pictures to show the condition. If you need any other pictures, please let me know. I pulled additional measurement details about this model size from Amazon (the last picture).  I've priced it at what the ebay selling rate seems to be.

Please let me know if you have any other questions.  All Reasonable Offers Considered.

Well packaged to avoid damage. 

Thank you!!