It may be difficult for Keystone to pinpoint what brand tire went on a particular trailer or model. One of their primary OEM providers is Tridet. They have 9 brands of ST tires and the GY G614 currently in inventory. Keystone May single out a brand for a particular trailer model. If so, what would be the reason? In OE tire selection the primary factor is the tire's load capacity.
Rainier is an OEM Tridet product.
West Lake is an OEM LionsHead product.