"MASTER,SET CONSISTING OF A HARDENED STEEL RING WHICH WILL BE SECURED IN A FIXTURE WHICH CONSISTS OF A HYDRAULIC CHUCK AND CLAMP/BACKUP PLATE;USED TO ACCOMODATE SETUP OF FIXTURE FOR MACHINING THE 5TH COMPRESSOR AIR SEAL FRONT O.D. SNAP DIAMETERS;1 IN X 15.332 IN DIA"