DK 
DK Super Readers Level 4 Horse Heroes 

Use your reading superpowers to learn all about some incredible horse heroes – a high-quality, fun, non-fiction reader – carefully levelled to help children progress.
Horse Heroes is a beautifully designed reader all about some of the world»s fastest, cleverest or most helpful horses.
The engaging text has been carefully levelled using Lexiles so that children are set up to succeed.
A motivating introduction to using essential non-fiction reading skills.