A system for aligning a prosthetic head component with a prosthetic stem, the system comprising : a mounting plate comprising: a first major surface that is planar; a second major surface that is planar and opposing the first major surface ; an adapter accommodation hole extending through from the first major surface to the second major surface ; and sizing indicia located on the second major surface ; a first fastener extending from the mounting plate ; and an adapter coupling plate slidably engaged with the mounting plate , the adapter coupling plate comprising: a third major surface that is planar and facing in a direction of the first major surface ; a fourth major surface that is planar and opposing the third major surface ; an adapter coupling hole extending through from the third major surface to the fourth major surface , the adapter coupling hole surrounded by the adapter accommodation hole ; and an indicator located on the fourth major surface to point to various portions of the sizing indicia as the adapter coupling plate slides against the mounting plate , wherein the adapter coupling plate is configured to slide against the mounting plate in a first linear direction parallel to the first, second, third, and fourth major surfaces . a mounting plate comprising: a first major surface that is planar; a second major surface that is planar and opposing the first major surface ; an adapter accommodation hole extending through from the first major surface to the second major surface ; and sizing indicia located on the second major surface ; a first major surface that is planar; a second major surface that is planar and opposing the first major surface ; an adapter accommodation hole extending through from the first major surface to the second major surface ; and sizing indicia located on the second major surface ; a first fastener extending from the mounting plate ; and an adapter coupling plate slidably engaged with the mounting plate , the adapter coupling plate comprising: a third major surface that is planar and facing in a direction of the first major surface ; a fourth major surface that is planar and opposing the third major surface ; an adapter coupling hole extending through from the third major surface to the fourth major surface , the adapter coupling hole surrounded by the adapter accommodation hole ; and an indicator located on the fourth major surface to point to various portions of the sizing indicia as the adapter coupling plate slides against the mounting plate , a third major surface that is planar and facing in a direction of the first major surface ; a fourth major surface that is planar and opposing the third major surface ; an adapter coupling hole extending through from the third major surface to the fourth major surface , the adapter coupling hole surrounded by the adapter accommodation hole ; and an indicator located on the fourth major surface to point to various portions of the sizing indicia as the adapter coupling plate slides against the mounting plate , wherein the adapter coupling plate is configured to slide against the mounting plate in a first linear direction parallel to the first, second, third, and fourth major surfaces . <EOS>