Farpoint stepped barrel 650nm laser collimator plus 2" Cheshire. Includes hard carrying case with fitted foam insert. All Farpoint laser collimators have a LIFE TIME Alignment Guarantee. We will realign any Farpoint laser collimator for free! But Farpoint lasers keep their factory alignment. This is due to our robust laser body and (most importantly) our unique alignment screw design explained below. Farpoint lasers have EIGHT alignment screws instead of six, four, or even three as in some other lasers. Instead of a staggered arrangement (top hole, bottom hole, top hole) that can allow the diode to move, BOTH ends of the laser diode are held in place by two sets of directly opposing screws for precise and lasting alignment. Again, only Farpoint lasers have this superior alignment screw arrangement with four DIRECTLY OPPOSING screws aligning the top of the laser diode and another four DIRECTLY OPPOSING screws aligning the bottom of the laser diode. Other lasers have fewer alignment screws and/or each end of the diode is not held firmly in position by directly opposing screws. Farpoint lasers have a small aperture (0.76mm or 30/1000 of an inch) for less speckling and more precise reading of the laser beam's position on the telescope mirror. Farpoint has the smallest aperture of any laser in the amateur astronomy market. Farpoint lasers are designed to fit precisely centered in focuser with no "focuser slop". For accurate and "meaningful real-world collimation", your eyepieces must be in the same position that your laser collimator was in when you collimated your telescope. Farpoint lasers are precisely machined for a tight fit that starts with the least possible error. Farpoint recommends not using your focuser's set screw at all. But if you use the set screw, do so loosely and install your eyepieces in exactly the same way that you install your laser.