... , Core Barrels, etc.The Geotool Core Barrel is a precision instrument designed to maximise core recovery in site investigation and exploratory ... % + core recovery in the most difficult formations.Size available:Q series Core Barresls: AQ, BQ, NQ, HQ, PQ, NQ3, HQ3T ... series Core Barrels: T2-56, T2-66, T2-76,T2-86, ...