This is not the standard model, but is instead the Heavy Duty model, that uses the 8 screws shown to make it super stable in all positions, and holds collimation through the rough knocks. Fits tube with an I.D. of 15" or larger. - Don't you wish that Kenneth was still marketing these?... Here's your chance!
I will ship this combo to anywhere in the 50 states for $75. - PayPal only please on this, as I need Christmas money - It's ok to use whatever credit card you have at no extra charge, as I am a premier member of PayPal.
Thanks for looking, and have a great evening!