Knee high boots are boots that have a shaft height that reaches to the knee.
About Low Heel:
Low heel are shoes which raise the heel of the wearer between 2/4" to 1 1/4" higher than the toes and provide moderate elevation. Low heel shoes come in a variety of styles, including sandals, loafers, mary janes, oxfords and boots. Low heel shoes are generally considered comfortable footwear, mostly due to their flexible, lightweight soles and low heels, which provide stability.
Metallic refers to a material that represents or resembles metals such as gold, silver, or pewter. Metallic articles are very shiny, and often embellished by metal materials.