In stock, ready to ship! This is designed to create an secure tube system using a Raynox DCR-150 or Raynox DCR-250 lens as tube lens. The Raynox DCR-150 is one of the most cost effective tube lens. You can read a review here: https://www.closeuphotography.com/200mm-tube-lens-test The difference to other tube systems is the larger diameter of 57 mm instead of the standard M42 extension rings. Normal M42 tubes are cheaper but can cause vignetting in the corners and edges of the image. Also the benefit of using 57mm extension tubes is that it has large enough inner diameter and grooved inside to reduce internal reflections as much as possible. We ship the tube rings completely disassembled or pre-assembled and set-up especially for your camera and Raynox lens. It includes the following: 1x MJKZZ VLE variable extension1x M42-to-M43 adapter ring (M42x1 M43x0.75)1x M42 to camera mount of choice (such as Canon EF or Nikon AI, please mention this in the textfield during the checkout process)1x M49 to RMS adapter3x Set of 3 segment extension tubes (7mm, 14mm, 21mm) Note pictures shown above include some other items for demonstration purpose only.