Sailun S637T ST225/75R15 F/12PLY . A heavy-duty, all-steel highway rib tire specifically designed for high-load capacity trailer applications, such as RVs, fifth wheels, and utility trailers. Its all-steel construction provides superior strength and durability, enabling it to withstand heavy loads and resist damage, which is crucial for a long service life. The tire features a five-rib design with wide grooves that enhance stability and effectively channel water away from the contact patch, improving wet traction and straight-line tracking. Multi-sipes on the tread improve grip in wet conditions and aid in heat dissipation, while a solid shoulder design resists irregular wear and promotes fuel efficiency. The S637T is engineered to deliver reliable performance, durability, and a low rolling resistance for a wide range of towing needs. All steel construction for maximum strength and load capacity. Multi-sipes improve traction in wet conditions and dissipate heat for prolonged tread life. All steel construction for maximum strength and load capacity. Five rib design for improved stability. Provides a smooth and peaceful driving experience, reducing road noise and enhancing comfort