You are bidding on a trio of Red Grass Guppies. 

The red grass guppy is a popular, selectively bred freshwater fish known for its bright red fins and delicate, grass-like spotting

A grass guppy is a vibrant, live-bearing freshwater fancy guppy strain (Poecilia reticulata) known for a fine, speckled dot pattern across its tail fin that resembles a field of grass.

See link below for more information and clearer pictures than the one I got. 

Size: Males grow to about 1.2 to 1.5 inches (3 to 4 cm), while females are larger, reaching up to 2.2 inches (5.5 cm). [1, 2, 3]
The "Grass" Pattern: Male grass guppies feature an ornate caudal (tail) fin covered in tiny, dense dots or speckles.
Color Variants: Popular types include Blue Grass, Red Grass, and Pink Grass, named after the primary background color of their body and tail. [1, 2]
Sexual Dimorphism: Males are slender and brightly colored with large, flowing fins. Females are silver-grey or olive, larger, rounder, and lack the intense patterning on their tails.