A device that helps to properly align and install large pistons in cylinders is disclosed. Large pistons and cylinders are heavy and difficult to handle, and if the piston is not inserted in the cylinder perfectly in line with the length of the cylinder, damage results. The device holds both the piston and cylinder being assembled, and has a number of alignment mechanisms. A laser is also used to set up the device and to ensure that the piston is straight with the center line of the cylinder for proper alignment and insertion.

The present invention is used to mark the location on a piece of jewelry being constructed where the bail or embellishments are to be placed. It uses a stationary vee-shaped stop and a vee-shaped planar sliding marking guide to clamp the jewelry piece by pressing against the bezel that forces the jewelry piece into a position to be marked or scribed on front and/or back of the piece. This allows slots where the marking tool is placed to be perfectly aligned with the centerline of the bezel. The sliding marking guide relies on the clamping force exerted typically by rubber bands or springs, to force the jewelry piece into position using a guillotine effect. To assure the mark on the work piece is clean and precise, the clamping force is applied to the moving marking guide which lays flat against the back of the piece being marked. The mark is typically applied with a marking pen or a scribe.