Here's a breakdown of what the product likely is:

Hosiery Fabric: The term "hosiery" in this context refers to a type of stretchy, knit fabric that is comfortable and soft. It is commonly used for sleepwear and casual clothing.

Trouser Shit: This indicates a two-piece night suit or loungewear set, consisting of a full-sleeved or short-sleeved top and a pair of long trousers.

LUD003612: This is the specific product code. The fact that the search results do not show a consistent brand or a large number of retailers using this code suggests it is a specific SKU for a single sller, rather than a widely-known model number.