All locomotives feature prototype-specific, separately applied "as-built" and/or "modernized" injection-molded and photo-etched metal detail parts.
Modernized A-units are equipped with all or some of the following as appropriate:

Eyebrow grabs - Nose-side ladder grabs
Sunshades - Ladder-rest grabs
Cab interior
All modernized units are equipped with the following:
Screw-mounted chassis
Individual window "glass"
Detailed battery boxes/air tank with brackets
Fully detailed 1200 gal. or 1500 gal. fuel tank with brackets
Partial or complete de-skirting
Lift lugs (as appropriate), front and rear
MU hoses, Coupler Cut Levers, and Air Hoses, front and rear
Athearn Genesis F units are now available in "Modernized" configurations and with an improved factory-installed onboard sound and DCC decoder!
Individual sound boards installed in both the A-unit and B-Unit.
Sound units are Dual-mode, compatible with both DCC and DC operations.
In DCC mode, all functions are NMRA compatible.
In DC mode, you can program an MU lashup with lead unit only horn, bell and lights.
In DC mode, all sound features are operated by a wireless handheld remote.
In DC mode, NO additional control box is required to operate advanced sounds.
In DC mode, six-button remote control allows control of the horn, bell, coupler crash, break squeal, dynamic brake and brake air release.
Additional DC mode programmable features allow for different bell and horn tones, coupler on/off, bell rate, directional lights on/off and volume control.
Fully functional headlights and Mars lights (where applicable) in both modes.
Operating back-up light (where applicable).
Genesis driveline with dynamically-balanced five-pole skew-wound motor and flywheels.
Directional constant lighting.