The numbers you provided refer to the tire size, which is a popular "wide profile" choice for trucks and SUVs. Tire Size Breakdown
You can find this size in several styles at retailers like Discount Tire or Custom Offsets : 305/50/20 Performance Tires for sale - eBay 90 531 305 50 20
Provides a broader grip on the road, improving responsiveness. The numbers you provided refer to the tire
While they can fit some stock rims, many experts recommend a rim width of at least 10.5 inches for the best performance and to avoid excessive wear. Common Options 90 531 305 50 20