The number "18100c" is likely a product code, SKU (Stock Keeping Unit), or model number used by Marks & Spencer (M&S) for a specific hair brush they sell, especially through their international or third-party retailers.

It is not a widely-known, descriptive product name, which is why general searches are difficult.

However, the search results strongly suggest that the hair brush products with similar numeric codes available from M&S resellers in regions like Pakistan are typically:

General Purpose Brushes: Often described as suitable for all hair types.

Various Shapes: Including Round and Paddle designs.

Simple/Basic Models: Sold at a lower price point compared to premium brands M&S also stocks (like Kent or Tangle Teezer).

In the context of Marks & Spencer's retail line, this code likely refers to a basic:

Round Hair Brush (for blow-drying and volume) or a

Cushion/Paddle Brush (for detangling and smoothing).