DT Competition Straight Pull 2.0/1.8/2.0 mm
You have to use 2.0 mm nipples / straight-pull
Spoke Lenghts for DT Swiss System-Wheels can be found with this tool:
For Straight-Pull hubs you can use the DT Swiss Spokes Kalkulator.
For Straight-Pull hubs you can use the DT Swiss Spokes Kalkulator.