WD My Passport HD fits perfectly (with it's cable wrapped up) in the case. The case is made with high quality materials, however, I wish its edges were a bit smoother and straight. In other words, the edges (where the seams meet) have bulges.
Perfect little case for the WD My Passport (I have the 1TB). It fits well and is made of nice material. Had it for a few months now and it does the job for me. Zipper is good quality and never gets stuck. Highly recommend this product for your hard drive. Cheers!