This armor was a modular component system rather than a fully integrated suit. As such, each individual system (helmet, boots etc.) may have had different features.
There were also plug-in points for various modules. One of these was the Hulkbuster add-on used when Hulk confronted Iron Man over the production of gamma bombs when part of Stane International. The two met at a production plant. Stark acknowledged that Stane had conducted many illegal and unethical operations, but explained that this news was nothing more than a smear campaign. The two were able to settle the dispute and dismantle the plant.
Repulsors and the uni-beam remained standard for the base unit. Boot jets were upgraded. A refractive coating helped against energy attacks.
Magnets located on the palms and soles as well as a grappling hook with cable were used for climbing. A loudspeaker was used to address crowds. Image inducers were upgraded to give off 'identifier signals,' fooling the Controller.
Various modules were available:
- Full Spectrum Scanalyzer with Adamantium-Tipped probe. 
- Magnetic Railgun Launcher with explosive shells. 
- Semi-Fluid Polymer Compound : energy-absorbent compound that shot out and covered its target
- EM Field Generator : attracted a lightning bolt to short out Ultimo.
- Gravimetric Field Generator : canceled out the pull of the Earth's gravity on whatever it was attached to.
- Polybond Adhesive Compound 
- Cryogenic Compact Module 
- Magnetic Compact Module : used magnetic field to polarize the target. Multiple modules could be used to polarize the target with mutually opposing states making the atoms of the target repel one another.
- Hypodermic injector 
- Microsurgery Equipment 
- Shoulder Mounted Weapons 
- Hulkbuster, it integrated a magno-hydraulic pseudo-musculature which provided greatly enhanced strength rated at 175 tons. Sensors were adapted to focus on detecting gamma radiation. It had impact-resistant carbon composite plating and an anchoring system.
- The Hulkbuster add-on was originally identified as an individual armor, Model 14, in the All-New Iron Manual. It was later reidentified as simply another form of the Model 13 in the Iron Manual.
- The Modular Armor is quite popular as it was/is usually used by the animated version of Iron Man and Capcom version of Iron Man.
- 85 Appearances of Iron Man Armor Model 13
- Media Iron Man Armor Model 13 was Mentioned in
- 23 Images featuring Iron Man Armor Model 13
- Item Gallery: Iron Man Armor Model 13
- Fan-Art Gallery: Iron Man Armor Model 13
Links and References