  We review the T_90 duration and hardness ratio of Swift Gamma Ray Bursts
(GRBs). We focus on GRBs with known redshift and review their gamma properties
in the GRBs rest frames. We find that GRBs number vs. T_90/(1+z) distribution
shows a separation between two classes at 0.65 s. Furthermore, we find that the
difference in hardness ratio between short and long bursts is not very
pronounced and depends on energy channels used for comparison.
