New Bosch GLL2-40 Compact Cross-line Laser Level
Bosch is bringing us a smaller more compact cross-line laser with their new GLL2-40. I have the older GLL2-50 laser that I purchased when it first came out, and judging by the photos, the GLL2-40 appears to be quite a bit smaller. After a quick look at the specs I can see that the GLL2-40 is smaller in length, width, and height. The smaller size does come in handy in many cases, but the small size of the laser does indeed come at a cost to the laser's accuracy. The GLL2-40 has an accuracy of ±1/8-in @ 30-ft, while the GLL2-50 is ±1/4-in @ 100-ft. So it would seem as though the GLL2-40 is in no way meant to be an upgrade to the 50, but rather another option in the Bosch laser lineup.
Other then the size and accuracy differences mentioned, the lasers have many of the same features. They are self leveling on both the horizontal and the vertical, and they can be locked out of level if needed. One of the features that insures the life of the laser is the pendulum lock that is automatically engaged when the laser is turned off. This prevents the laser's self-leveling optics from rattling around during transport.
The GLL-40 is listed on Amazon for around $175 and is about $25 cheaper then the Gl2-50. It includes three AA batteries, a soft case and a wall mount. The wall mount is not adjustable like the one included with the 50, but it has your basic features including a magnetic mount, a rotatable base, and tripod mounting holes for both 1/4-20 and 5/8-11 threads.