"MASTER,SET USED TO ACCOMODATE SETUP FIXTURE FOR MACHINING THE 4TH,6TH, OR 7TH STAGE COMPRESSOR AIR SEAL FRONT O.D. SNAP DIA;CONSISTS OF A HARDENED STEEL RING WHICH WILL BE SECURED IN A FIXTURE WHICH CONSISTS OF A HYDRAULIC CHUCK AND A CLAMP/BACKUP PLATE"