64GB OWC 2400MHZ DDR4 SO-DIMM PC4-19200 2x32GB Memory Upgrade Kit for iMac 21.5" 4K (Mid 2017) by OWC

Upgrade the memory of your compatible 21.5" Apple iMac and then have the tools to reseal its display with the 64GB DDR4 2400 MHz SO-DIMM Memory Upgrade Kit with Adhesive Tape Set from OWC. This kit includes two 32GB DDR4 memory modules that fit 260-pin SO-DIMM slots, and the modules have been specially configured for the mid-2017 21.5" Apple iMac with 4K Retina display. Operating at 1.2V, the memory has a 2400 MHz clock speed, a bus speed of PC4-19200, and a low-noice, 8-layer PCB design.

Included in this kit is an adhesive tape set that can be used to reseal the display of your compatible 21.5" iMac once installation is completed. Professional installation is highly recommended.

Compatibility
This memory kit and included memory is for 21.5" Apple iMac 4K 2017 models only. Memory provided in this kit has been specially configured for the 21.5" model and is not compatible with 27" Apple iMac models. The included memory is compatible with Windows laptops that support DDR4 2133 or 2400 modules.

Professional Installation Highly Recommended
While this upgrade kit itself should not void your warranty, the installation process is very complex. Professional installation is highly recommended.