The Canon EF 400mm f/5.6L is a professional-grade telephoto lens designed for Canon's full-frame and APS-C DSLR cameras. It features a fixed focal length of 400mm, making it ideal for wildlife and sports photography, where capturing distant subjects is essential. The lens is known for its sharp image quality and fast autofocus capabilities. Weighing approximately 1.3 kg (2.8 lbs), this lens is relatively lightweight for its class, allowing for easier handling during extended shooting sessions. It also includes a weather-sealed construction, providing durability in various environmental conditions, which is beneficial for outdoor photographers.