This is a 2" gattler laser with tuBlug with 1mm stop and grid attachments for collminating newts and other scopes.
Use the 1mm stop to throw a spot to center the secondary to the primary then use the tuBlug without the stop to show a reflection of the primary donut on a screen outside the scope to align the primary by centering the center of the donut on the display panel as per a barlowed laser. The grid attachment allows you to center the secondary under the focuser in the first instance by shooting a grid from the focuser to the secondary and onto a user supplied A4 paper sheet.
A good read on these devices is
here.
Plastic protectors included.
$275 posted.