Yes, the Corsair Mac Memory model (2 x 16GB, 2666 MHz, DDR4-RAM, SO-DIMM) with the product ID CMSA32GX4M2A2666C18 is compatible with the iMac (Retina 5K, 27 inch, 2019).

- It uses SO-DIMM modules with 260 pins and a clock frequency of 2666 MHz, which corresponds to the specifications of the iMac (Retina 5K, 27-inch, 2019).
- The model is specifically designed and tested for Mac systems to ensure optimal performance and compatibility.