The Macro 150 is the updated and improved version of the B150-B. This upgraded macro focusing rail is more compact and lighter than the previous version. Focus stacking is easier than ever with the Macro 150 thanks to a new zeroing dial and a lead screw with a 1mm pitch, meaning one revolution of the knob equals exactly 1 mm of travel. However, the largest improvements are in the performance: backlash and drift are essentially eliminated due to our tight-tolerance CNC-machined components. The need to adjust the stage tension is also eliminated, and is now individually set during assembly. Load capacity is also increased to 20lbs. What has not changed is the superior build quality, the same travel range, and, as always, everything is made in the USA.