This tele-converter will increase the focal length of the lens that is attached to the front of it by a factor of 1.4 X. It is in near mint cosmetic condition showing just very minor signs of having been mounted on a camera. Optically, electronically, and mechanically it is perfect. Therefore a 50mm lens becomes a 70mm or a 135mm becomes a 190mm lens. Keep in mind that in increasing the focal length you are "losing" 1 f/stop.
This device also makes a great close-up or macro device, because the closest focusing distance of your lens remains the same, but the image size is magnified 1.4 times. Full frame teleconverter with 5 element/5 groups design. No HSM or SDM contacts. Comes the original front & rear lens caps and a very nice leather pouch.The item "Pentax AF 1.4X Sigma 5 Element MultiCoated Teleconverter KAF Hard to Find MINT" is in sale since Thursday, February 11, 2021. This item is in the category "Cameras & Photo\Lenses & Filters\Lenses". The seller is "mrebee" and is located in Hales Corners, Wisconsin. This item can be shipped to United States, all countries in Europe.