"The HD PENTAX DA AF 1.4x AW rear converter features weather-resistant construction to prevent the intrusion of water and moisture into the lens barrelwhen paired with weather sealed PENTAX DSLR bodies and lenses. The user is assured of greater durability and reliability when shooting in rain or mist, as well as at locations subject to a spray or splash. Treated with HD coating, a PENTAX-exclusive multi-layer lens coating, enjoy higher light transmittance and lower reflectance than conventional multi-layer coatings. This means it produces sharp, clear images free of flare and ghost images, even under such adverse lighting conditions as backlight. The HD PENTAX DA AF 1.4x AW rear converter offers a 40% increase in focal length when mounted between the body and lens, yet has an extremely small form factor. Measuring only 20 millimeters (approximately 0.8 inches) long, its compact, lightweight design allows the user to more easily reach out to distant subjects. The minimum focusing distance of the lens is retained, allowing for the capture of larger, more detailed images in close-up situations. (*When this rear converter is mounted, the lens maximum aperture will be smaller by 1 stop. Auto Focus and Auto Aperture functionality is retained when using the HD PENTAX DA AF 1.4x AW rear converter. The rear converter works flawlessly with both the camera-driven AF system and the lens-driven AF system (such as the SDM- and DC- series lense|Weather Resistant|PENTAX HD Lens Coating|1.4X Magnification in a Compact Form Factor|Auto Focus and Aperture Compatibility"