The web site indicates that a -2D has 1/4 inch NPT threads. My invoice says I got a -2D, the package says -2D, but the coupler did not have 1/4 threads, more like 1/2 inch threads.
Bob M
14.02.2020
The AN910 couplings that I received had VERY tight threads. It is as if the aluminum were machined to the specs, then the anodizing was done, shrinking the opening dimensions. The other NPT parts could only be threaded in about 1 turn before becoming tight. They should thread at least 4-5 turns before becoming tight. These particular parts might be unusable, unlike Aircraft Spruces usual high standards.