This opportunity involves two distinct items: a 155mm Calibration Guide Tube Assembly (GTA) for use with LVDT Scanner Assemblies on M284 and M776 cannon models, and a 155mm Self-Propelled Sensor Delivery Unit (SDU). The GTA must allow calibration ring removal while attached to the cannon muzzle, and the SDU must push or pull sensors over at least 35 feet while interfacing with existing YPG-owned sensors. The SDU requires a muzzle adapter for 155mm gun tubes, a flexible cable with a non-scratch cover, and data acquisition capability over the full bore length. Performance specifications for the SDU include linear resolution of 0.010 inches or better and a uni-directional position repeatability goal of 0.040 inches or better. No timelines, budget amounts, or performance location were specified in the description.