Following a first shipment of defective models, the seller (Toslde, Germany) m returned within 4 days of a new Optical Bay, which has everything he worked on after the installation (easy, about 20 minutes total). So I see my note and put 5 because works perfectly. The packaging is light, but perfectly safe for the product. I finally have the place more in my macbook was cramped with 256GB SSD!