Frog-leather chaps can be obtained from Reldak in the market place in Dorgesh-Kaan. They can also be looted from Dorgesh-Kaan average chests, which require 52 Thieving to pick. This piece of armour requires 25 Defence and Ranged to wear.
The full frog-leather armour set consists of:
All Junk chance: 72.5 Junk chance: 72.5