To get the most out of your Newtonian scope you really need to align or collimate the mirrors.
It can take some time getting used to aligning both the secondary and primary mirrors and this
short collimator can make it much easier. The short collimator for mirror (reflector) telescopes
has a 45 degree plate for easier visual accuracy. Collimation is the alignment of elements inside
an optical system like a telescope. Colimating a telescope consists of adjusting the tilt and position
of the mirrors and lenses to ensure that the focal point reaches optimum focus at the point from
which the image will be viewed (the eyepiece or possibly a camera).