How to install an SSD on a 15-inch Retina MacBook Pro
How to use an NVMe drive to upgrade your Mac's SSD | AppleInsider
How-To: Upgrade the SSD in your MacBook Air or Retina MacBook Pro, boosting size & speed - 9to5Mac
Amazon.com: MCE Technologies 2TB SSD for MacBook Pro 2015 15-inch Only: PCIe-Based 4 Lane (x4) NVMe 8.0GT/s SSD Flash Storage Upgrade - 2900MB/s Read, 2100MB/s Write, Requires macOS 10.13.x (High Sierra) or
Amazon.com: MCE Technologies 2TB SSD for MacBook Pro 2015 15-inch Only: PCIe-Based 4 Lane (x4) NVMe 8.0GT/s SSD Flash Storage Upgrade - 2900MB/s Read, 2100MB/s Write, Requires macOS 10.13.x (High Sierra) or
SSD Upgrades for 2013, 2014, and 2015 MacBook Pro
Amazon.com: 256GB SSD Hard Drive for Apple MacBook Pro Air 11" 13" 15" A1502 A1398 A1465 A1466 (Late 2013-2015) / OSX Sierra/Mac Pro A1481 : Electronics
MacBook Pro 13" Retina Display Early 2015 SSD Replacement - iFixit Repair Guide