"RoHS-compliant" means that the PCBs are fabricated with either immersion gold, immersion palladium-gold, immersion tin or HAL-lead-free. Which of these surface finished is eventually selected by LeitOn for your pritned circuits depends on the current order situation. This option is the cheapest because you leave the choice to us. You may chose an explicit surface finish for a surcharge.
In case you are not sure whether RoHS-compliant surfaces do meet your requirements we offer detailed information about all the surfaces on this website above. To begin with, all surface finishes offered under the label "RoHS compliant" in our online calculation are solderable but may differ in planarity, bonding capability, storage time and sensitivity.