The Tost Aero 200x50 6-ply (6PR) tire, part number 063191, is an aviation tailwheel tire used primarily on gliders and light aircraft ground handling systems. It is designed for 200 mm × 50 mm wheel assemblies and is commonly installed on tailwheels of modern sailplanes.

This tire is part of the Tost Flugzeuggerätebau GmbH aviation tire line, known for producing durable, high-load aircraft tires used in gliding and general aviation operations.

Its primary features include:
6-ply reinforced aviation tire construction (6PR)
Size: 200 × 50 mm (tailwheel / small aircraft wheel standard)
Tube-type design (requires inner tube installation)
Designed for gliders and light aircraft tailwheel systems
High wear resistance for grass and unpaved runways
Static load capacity typically around 200–250 kg per tire 
Lightweight aircraft-grade rubber construction
Optimized for long service life and repeated landing cycles

This tire is widely used in sailplane operations because it balances low rolling resistance with durability, making it ideal for training fields and frequent takeoff/landing cycles on grass airstrips.

In short, the 200x50 6PR (063191) is a standard glider tailwheel tire focused on durability, light weight, and reliable ground handling performance.