24 inch long flexible waveguide AS4C-112-24 "Flexaguide" by Airtron.
Flange size: 48x48mm, 4 off 3.5mm tapped bolt holes, very approx 12.5x29 r1.5 aperture,
Status: NOS (New Old Stock) unused, in original packaging and sealed with original plastic end caps and inspection certificate. Ex USAF
Airtron now part of cobham Industries.