Howie Glatter TuBLUG 1.25" Newtonian for Laser Collimator

The Howie Glatter Tublug is a great product and one that has significant advantages over the BLUG:

First, the Tublug places the return shadow of the reinforcement tab at a very convenient, easy-to-see location OUTSIDE the focuser rather than at the inside of the focuser requiring you to peer between the truss poles in order to see the shadow. (Of course, the BLUG is not very useful at all with "solid tube" dobsonians!)
Secondly, many people are a bit cautious about having to insert the BLUG into the inside of the focuser since there is always the remote possibility that you may drop it onto your primary mirror while attempting to insert it into place.

For these reasons many "truss pole" dobsonian owners choose to go with the Tubllug. the only disadvantage to the Tublug is that iit will force you to part with a little bit more of your hard-earned savings!

The tuBlug™ is the answer for those who want to Barlow-collimate their primary from the back of the scope, but have a solid tube Newtonian, or can't be bothered to slide their shroud up.

It's a Blug (Barlowed laser plug), containing its own lens and shadow screen that fits within a side cut-out tube, the combination being known as a tuBlug. Like the collimator self-Barlow attachment or the Blug, it uses the Barlowed laser principle to project a silhouette shadow of the primary mirror collimation mark back onto its white screen, where the shadow is centered to collimate the primary. The tuBlug comes in 1¼" and 2" sizes, fits any focuser, and can be used with any well-centered laser collimator.

Unfortunately, the standard Blug which fits to the inner end of the focuser drawtube inside the telescope, can not used as a tuBlug because it must necessarily have a shoulder which will seat it squarely against the end of the drawtube. The shoulder will be larger than eyepiece diameter, which will prevent the Blug from fitting in the side cut-out tube.