OWC Offers Dual DisplayPort and dual HDMI Adapter for Thunderbolt 3 Macs or PCs
See also: computer display topics.
OWC is now offering two adapters for Thunderbolt 3 that facilitate connecting displays on Thunderbolt 3 Macs or PCs.
In MPG’s view, the best investment is the OWC Thunderbolt 3 Dock, since it provides both a Mini DisplayPort and USB ports and a pass-through Thunderbolt 3 port. But for simple needs, these adapters are less expensive.
OWC Thunderbolt 3 Dual DisplayPort Adapter
Get Thunderbolt 3 Dual DisplayPort Adapter at MacSales.com.

This adapter supports a 5K external display or two 4K displays via a Thunderbolt 3 port. Plugging in display(s) means a DisplayPort to Mini DisplayPort cable is needed for displays with a Mini DisplayPort port. (not MDP to MDP), so for such displays, purchase a DisplayPort to Mini DisplayPort cable.
NEC supplies DisplayPort-DisplayPort cables with certain professional displays, so no need for an extra cable (assuming the user has kept the supplied cables!).
Up to 5120 x 2880 Resolution @ 60Hz. Compatible with any Mac or PC with a Thunderbolt 3 port. They're bus powered and come with an integrated Thunderbolt 3 cable - so all you need to do is plug in your monitors. Perfect for adding extra screen space to your laptop workflow, increasing productivity, setting up a powerful desktop workstation with the monitors you already have, or immersing yourself in a rich gaming experience.
OWC Thunderbolt 3 Dual HDMI Adapter
Get OWC Thunderbolt 3 Dual HDMI Adapter at MacSales.com.
Up to 3840 x 2160 Resolution @ 60 Hz. Compatible with any Mac or PC with a Thunderbolt 3 port. They're bus powered and come with an integrated Thunderbolt 3 cable - so all you need to do is plug in your monitors. Perfect for adding extra screen space to your laptop workflow, increasing productivity, setting up a powerful desktop workstation with the monitors you already have, or immersing yourself in a rich gaming experience.