Going off the Amazon description, this flash can't act as a master flash. The M mode is for "manual." It is not E-TTL capable, either.
Canon 6d, t1i, 20/2.8, 28/1.8, 40/2.8, 50/1.8II, 100/2.8 macro, 70-300/4-5.6, g1x, 430exII, 90ex
Elan 7N with 28-105/3.5-4.5II, Rebel G with 35-70/3.5-4.5, A-1 with 28/2.8, 50/1.8, and 135/3.5