This 3D-printable DFAT (Dryfire, Focus, Adaptive, Training) adapter allows your high-magnification rifle scope to focus at extremely short distances (1.5-3.2 meters). By using inexpensive optometrist trial lenses, you can practice reticle leveling, position building, and "steadying the wobble" without ever heading to the range.

Key Features:

• Affordable Precision: Uses standard 38mm trial lenses from AliExpress.
• Indoor Training: Brings your parallax down to living-room distances while keeping the reticle sharp.
• Custom Fit: Specifically designed for the Athlon Ares ETR Gen 2 4.5-30x56mm, but may fit other 56mm objectives.
• Simple Install: Friction-fit "slide-on" design.

Bill of Materials (BOM)

To complete this build, you will need:

1. The Printed Parts: Adapter body.
2. Optometrist Trial Lens: 38mm diameter with metal rim.
   1. +0.25 Diopter: For focus at ~3.2m
   2. +0.50 Diopter: For focus at ~2.4m
   3. +0.75 Diopter: For focus at ~1.5m
   4. Search Term: "Optometry Trial Lens" or "Trial Lens Single Piece".
3. Glue: A small drop of super glue to secure the lens in the housing.