removable, but difficult to replace, as it is a proprietary format of SSD storage. On June 5, 2017, Apple updated the line with Intel Kaby Lake processors and newer graphics cards. A 128 GB storage option was added for the base 13-inch model, down from the base 256 GB storage. New symbols were introduced to the control and option keys. On July 12, 2018, Apple updated the Touch Bar models with Intel Coffee Lake quad-core processors in 13-inch models and six-core processors in 15-inch models, updated graphics cards, third-generation butterfly keyboards that introduced new symbols for the control and option keys, Bluetooth 5, T2 SoC Chip, True Tone display technology, and larger-capacity batteries. The 15-inch model can also be configured with up to 4 TB of storage, 32 GB of DDR4 memory and a Core i9 processor. In late November the higher-end 15-inch model could be configured with Radeon Pro Vega graphics. On May 21, 2019, Apple announced updated Touch Bar models with newer processors, with an eight-core Core i9 standard for the higher-end 15-inch model, and an updated keyboard manufactured with "new materials" across the line. On July 9, 2019, Apple updated the 13-inch model with two Thunderbolt ports with newer quad-core eighth-generation processors and Intel Iris Plus graphics, True Tone display technology, and replaced the function keys with the Touch Bar. macOS Catalina added support for Dolby Atmos, Dolby Vision, and HDR10 on 2018 and newer models. macOS Catalina 10.15.2 added support for 6016x3384 output on 15-inch 2018 and newer models to run the Pro Display XDR at full resolution. The 2019 MacBook Pro was the final model that could run macOS Mojave 10.14, the final macOS version that can run 32-bit applications such as Microsoft Office for Mac 2011. A report by AppleInsider claimed that the updated "Butterfly" keyboard fails twice as often as previous models, often due to particles stuck beneath the keys. Repairs for stuck keys have been estimated to cost more than $700. In May 2018, two class action lawsuits were filed against Apple regarding the keyboard problem; one alleged a "constant threat of nonresponsive keys and accompanying keyboard failure" and accusing Apple of not alerting consumers to the problem. In June 2018, Apple announced a Service Program to "service eligible MacBook and MacBook Pro keyboards, free of charge". The 2018 models added a membrane underneath keys to prevent malfunction from dust. As of