The profiles of Type II bursts also vary greatly, but are generally characterized by
rapid successions of bursts a few minutes apart
sudden drops in flux without a gradual decay from peak values
no spectral softening in decay
sustained peak values of flux seen in longer bursts (resembling a flat top on the graph of photon count rate vs. time)

Notably, Type II bursts have been observed in only two sources:
MXB 1730-335 (the Rapid Burster)
GRO J1744-28 (the Bursting Pulsar).

http://www.activeone.com/davidjlin/NeutronStar/glossary/TypeII.html


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however, type I burst has a feature of fast rise and slow decay.