This is a Parke (パーク) trumpet mouthpiece, model 640 278 25 (R5) one-piece type.
Rim:
R5 rim, based on Mount Vernon, equivalent to Bach 1-1/2 (inner rim is not too sharp).
Cup:
278 cup, depth between 1.5C and 1C.
Throat:
25
Backbore:
Equivalent to Bach #24 (Symphonic).
I believe these specifications are also suitable for rotary valves.
This one-piece type is rarely available.
Used for approximately 1 week.
Daily Cleaning: Use a soft brush or damp cloth to gently wipe away dirt. Avoid harsh chemicals. For mesh areas, use diluted mild detergent and a soft brush.
Drying: Air dry in a cool, shaded place after cleaning. Avoid direct sunlight or high heat, which can cause fading and glue deterioration.
Storage: Stuff with paper to maintain shape when not in use. Store in a dry, ventilated area to prevent mold. Rotate between multiple pairs to extend lifespan.
Usage Notes: Designed for basketball. Not recommended for hiking, long-distance running, or other specialized sports where different performance features are required.
The product does what it’s supposed to do. Nothing extraordinary, but it performs its function well. Delivery was quick and smooth.