MID-70'S OEM STYLE MASTER CYLINDER, BUILT IN BLEEDERS. SPECS. 1" BORE, SHALLOW HOLE 9/16-24 AND 1/2-18 PORTS ON LEFT SIDEFeatures built-in bleeders & 70's OEMlook. Specs: 1" bore, Shallow hole,9/16-24 & 1/2- 18 ports on left side.Mid 70's