j5create Mini DisplayPort to Dual 4K HDMI MST Adapter, Compatible with Microsoft Surface Pro, Surface Book, HP OMEN 15-CE051NR and More (JDA156): Amazon.co.uk: Electronics & Photo
StarTech.com 2-Port Multi Monitor Adapter - DisplayPort 1.2 MST Hub - Dual 4K 30Hz or 1080p - USB Bus Powered - Video Splitter for Extended Desktop Mode on Windows PCs Only -