This assumes that the user is a Brawler, Monk or has the Improved Unarmed Strike Feat.
- Cestus are gauntlets which deals 1d4 damage and has Critical Treat Range of 19-20×2.
- Improved Unarmed Strike pretty much say you can use your whole body as weapon and considered armed. Medium sized PCs deal 1d3 damage with Critical Threat of ×2.
- Now in regards to using Cestus, I assume the its Critical Threat of 19×2 on occurs with Punches or other attacks the require Fist and or Forearm.
Now besides taking the Improved Critical Feat, are there other ways to increase the Critical Threat range of your whole body with your Unarmed Strikes? Maybe Plate Greaves for Kicks, Spiked Elbow/Knee Pads, or even an entire set of Spiked Armor? Would an Amulet of Might Fist with Keen as an or one of the Enhancement Bonus(es) work?