A hookless rim has straight internal sidewalls without the familiar hook above the tyre bead. Before buying a tyre, compare its exact model and size with the combinations permitted by the rim manufacturer. Schwalbe also stresses the importance of respecting minimum tyre widths.
Zipp requires tyres approved for its TSS, or Tubeless Straight Side, rims. A “tubeless” label alone is insufficient. An inner tube is also allowed only with a compatible tyre; it does not make an unsuitable tyre compatible. If a model is absent from a compatibility list, consult the tyre manufacturer rather than judging by appearance.
Look up the specific wheel’s pressure limit: the Zipp 303 XPLR S, for example, lists a maximum of 3.45 bar. That is a limit, not a riding pressure recommended for everyone. The lowest applicable maximum for the tyre, rim and complete combination must be respected. Before shopping, record the wheel model, internal rim width and exact tyre size to make compatibility easier to check.