From the back of the book:
The knight is one of the most highly trained combatants ever to enter the field of battle. Expert with a variety of weapons and particularly effective when astride his trusty charger, when under pressure he draws extra strength from his chivalric vows. He is perhaps the best protected of all character classes, typically wearing full plate armour but proficient with a variety of extra-heavy armours for special purposes. A knight’s noble birth often provides him with a far superior array of equipment than most characters have access to.
This is the 5th book of the Power Classes series from Mongoose Publishing. Designed to be seamlessly slotted into any fantasy-based d20 system game, each of these mini-supplements introduces an entirely new core character class, adding a whole new dimension to campaigns. Players will find full details on how to use the new character class, greatly increasing the wealth of options they are presented with by the core rulebooks while Games Masters may revel in the wide variety of new classes they have at their disposal for non-player characters in their campaigns. Each Power Class booklet can provide hours of gaming enjoyment at an all new low cost.