The EF 400MM f/4 Ultra Light DO (Diffractive Optics) IS (Image Stabilizer) USM (Ultrasonic Motor) Lens gives eloquent testament to Canon's innovations and advancements in the field of optical technology. Attach an EOS EF 35mm lens to your camera, and you enter a dimension of virtually unlimited photographic possibilities. Diagonal Angle of View - 6° 10' Focus Adjustment - Inner focusing system with USM Closest Focusing Distance - 3.5m / 11.5 feet Filter Size - 52mm Drop-In Dimensions - 5.0W x 9.2L Weight - 4.3 pounds