Just one bubble for sure. Use a fine pen and mark your own lines with an accurate spirit level as a guide. The laser must be adjusted vertically and horizontally. I removed all the screws, including those under the batteries and under the Qooltek label on the other side. Detach the laser module from the plastic holder and clean the adhesive. The module is tight, but can be adjusted. I placed it against a block in an angled groove on my table saw with another block on the fence to catch the point. When you're done, put a dab of crazy glue on the laser module in the plastic mount. Advice. Gently pull out the vertical/horizontal line lens so that the dot is much brighter than the lines.