We present deep F606W , F814W ACS photometry of the recently discovered globular cluster B514 , the outermost known globular in the M31 galaxy .
The cluster appears quite extended and member stars are unequivocally identified out to \sim 200 pc from the center .
The Color Magnitude Diagram reveals a steep Red Giant Branch ( RGB ) , and a Horizontal Branch ( HB ) extending blue ward of the instability strip , indicating that B514 is a classical old metal-poor globular cluster .
The RGB locus and the position of the RGB Bump are both consistent with a metallicity [ Fe / H ] \sim - 1.8 , in excellent agreement with spectroscopic estimates .
A preliminary estimate of the integrated absolute V magnitude ( M _ { V } \lesssim - 9.1 ) suggests that B514 is among the brightest globulars of M31 .