These Optec extension tubes are made to fit an Astro-Physics 2.7-inch connection; these spacers will add either 0.5-inch, 0.75-inch, 1-inch, 1.5-inch, or 3-inch to your path length. 

Each spacer has a clear aperture of 2.52-inches (64 mm) and threads on with 24tpi.

 

These two sets are listed on the size tab:

- - The 4-Piece set includes 1 each of the 0.5-inch, 0.75-inch, 1-inch, and 1.5-inch spacer lengths.

- - The 5-Piece set includes 1 each of the 0.5-inch, 0.75-inch, 1-inch, 1.5-inch, and 3-inch spacer lengths. 

 

Spacer Lengths:

• 0.5-inch
• 0.75-inch
• 1-inch
• 1.5-inch
• 3-inch
• 4-Piece Set: 1 each of the 0.5-inch, 0.75-inch, 1-inch, and 1.5-inches
• 5-Piece Set: 1 each of the 0.5-inch, 0.75-inch, 1-inch, 1.5-inches, and 3-inches