For SCT owners, the 45 degree face gives you a clear view of the collimator from the supplied adaptor. The laser is a class IIIA, 650 nm laser diode of less than 5 milli watts. It is considered safe for consumer use, but you should avoid letting the beam enter your eye, directly or after reflection from a mirror. It is OKAY to look at the scattered light from the red spots where the beam hits the mirrors.
The collimators take two AAA batteries (included). There is a one year Kendrick warranty for defects in materials and workmanship on the collimators.