When I had my 2011 15" MBP I bought the overpriced OWC Data Doubler Optibay Caddy for $70. When my brother got his 2012 13" MBP I decided to search for a cheaper, yet acceptable alternative. I landed on this $10 caddy from Amazon with mostly good reviews, some mixed reviews and some negative reviews stating it didn't fit or it didn't have screw holes to secure the HDD or included screws. For $10 and Amazon's amazing return policy, I took the chance and bought it. http://www.amazon.com/gp/product/B0058AH2US/ref=oh_details_o00_s00_i00 The caddy came with includes screws and it DID have screw holes to secure the HDD to the caddy itself. Its fitment was flawless and it bolted right in with no issues what so ever. Performance was as expected from a slow 5400RPM 500GB HDD. Overall, very satisfied with the product, especially for $10. I do NOT see how anyone who can justify spending $70 on a OWC Caddy because they slap a "mac compatible" or "just works" label on their product. This $10 caddy is every bit as functional and it also "just works".