I have recently got this useful tool for machine alignment - ND50 long distance laser designator at LaserTo.com. The laser body is round and in the range of 3/8-1/2 inch in diameter so be held on a collect. The laser itself will be rotating in this collect. It is a sustained, switchable (not momentary push button on/off).
This 532nm laser designator has amplified coherent light, which is the most efficient light for long distance illumination. This fully o-ring sealed for dust and water design, fully multicoated optical lens systems and rotary optical beam collimator allow it with quick adjustment of beam diameter and intensity.
This long distance laser designator has high reliability, high stability, long life and low price, which has high quality green laser module, optical glass lens, driver circuit and housing.
It is an useful too for laser alignment, aiming and positioning, hunting and spotting, outdoor hiking. Anyway, it is most useful to alignment for me.