Slick Cuirass 2014
Armor, common
This suit of leather armor has a shiny, greasy look to it. While wearing the armor, you have advantage on ability checks and saving throws made to escape a grapple. In addition, while squeezing through a smaller space, you don't have disadvantage on attack rolls and Dexterity saving throws.
Source: Vault of Magic (Kobold Press) · License: OPEN GAME LICENSE Version 1.0a details