This is an authentic Rolex case-back for a Rolex GMT Master reference 16750 or 16753. It is also the correct service case-back for the earlier 1675 GMT Master. The case-back is used, but in very fine condition and unpolished, with only a few superficial marks on the back that could be easily brushed/polished away. I am in the US. My asking price is $600 (reduced from $825) by fee-free PayPal or bank wire. Regular PP is ok + fees for established members. Shipping included in the US, surcharge TBD for international shipping. Links to my selling and buying feedback are below, and I'm happy to share personal information by direct message. https://omegaforums.net/threads/dan-...-seller.78044/ https://omegaforums.net/threads/dan-...-seller.79576/ https://omegaforums.net/threads/dan-...d-buyer.80126/ https://omegaforums.net/threads/dan-...ss-with.80035/ https://forums.watchuseek.com/f63/gr...s-4897643.html https://omegaforums.net/threads/dan-...seller.102116/ https://omegaforums.net/threads/dan-...seller.102652/