When I use a Prestige Token to Unlock Gear, what happens?

Modern Warfare 3 introduced the concept of the "Prestige Token," and one of its uses is to "Unlock Gear." I'm trying to decide if I want to invest any of my tokens in this category. Can someone explain what this means precisely?

What I'm curious about is:

• What can I unlock? Just weapons, or can I unlock equipment or Perks?
• How long does it stay unlocked? For just the next Prestige, or for all my other Prestiges as well?
• If I can unlock Perks, do I get to keep the Pro version of the perk?
• Do I get to keep my Weapon XP on a weapon if I unlock it?
• Do weapon challenges reset on an unlocked weapon?
• Do weapon proficiencies, attachments, and camo reset on an unlocked weapon?

Solution 1:

You can unlock any type of item (primary, secondary, equipment, perk, death streak) with a prestige token and it will stay unlocked for your entire MW3 prestige career

You will need to re-earn the pro version of the perk that you chose to unlocked with your prestige token.

All items (challenges, attachments, weapon level, weapon proficiency and camo) reset when you prestige in MW3.

This feature is available after prestige level 1.