Detected rotators in the overall context of the open cluster. Top: colour-period diagram for members of NGC 2281. It features a clear and well populated slow rotator sequence running diagonally from higher mass stars with periods ≲5d up to P_rot ≈ 20 d for the least massive stars in our sample. Only two outliers are evident above the sequence. Below this sequence, we find a few fast rotators, likely outliers, among the early-K stars. Among the lower mass stars, we find several faster rotating stars providing evidence that this open cluster is certainly younger than the Hyades. Potential binaries are marked with squares. Bottom: corresponding colour-magnitude diagram of the rotators (black) and non-rotators (small open circles).