This item is a Size L Majestic Los Angeles Dodgers batting practice or warmup jersey. It features the classic royal blue body with contrasting white raglan sleeves and a V-neck collar. 
 
Measurements - Chest - 44cm.
          Drop (front) - 51cm
          Drop (rear) - 61.5cm.
          Neckline - 13.5cm.
 
 
Product Details
Brand: Majestic.
Design: Royal blue mesh body with white sleeves and trim; "Dodgers" script across the chest and the "LA" logo on the left sleeve.
Type: Often identified as a Cool Base or Authentic On-Field batting practice jersey, designed for breathability and performance.
Features: Includes a lower locker tag for player identification, typical of official team apparel.
 
 
Research confirms that Style NO. MBY8 identifies this as an official Majestic MLB replica "Cool Base" batting practice jersey. 
 
The production details on your tag provide a clear timeline for this specific garment:
Production Date (Dec-09): The jersey was manufactured in December 2009.
Season Code (S10): It was produced as part of the Spring 2010 retail collection.
Design Era: During this period (late 2000s), Majestic's replica jerseys were highly regarded for their durability, often featuring stitched/embroidered team logos (unlike newer versions that often use heat-pressed patches). 
 
Verified Authenticity Markers
The information on the tag aligns with official Majestic manufacturing standards for that era: 
 
Consistent Codes: The presence of a Factory ID (650821) and a matching Style NO. (MBY8) is a strong indicator of a genuine product.
Tag Type: This specific "pro tag" layout (showing date and style) was standard for high-quality retail replicas meant for fans, rather than the "numeric" sized jerseys (e.g., size 44, 48) worn by players on the field. 
 
It has minor marks.