We acquired this high end treadmill years ago and aren't using it much these days. The tredbelt just broke and instead of repairing it we are looking to give it away to anyone that is willing and able to pick it up and haul it away. It's quite large and heavy but there is a process to move it safely (that's how we got it in). The treadmill works perfectly otherwise and is a very high end (and heavy duty model). More information at: https://www.treadmilldoctor.com/nautilus-t714-treadmill-review?srsltid=AfmBOoof7t_E0Z9TxYNNlJ5KR5aIKgRLwlJ5hp1VkHHHJbTBoOpVcJNq
It looks like these belts are available for ±$100 from a variety of online sources, including Amazon. Please double check the size/type and fit as I just looked quickly. https://www.amazon.com/SportSmith-Nautilus-Treadmill-Walking-Running/dp/B071JMNTQ1
Free to anyone willing and able to haul it away.