DSLRKIT 8 channel Wireless Studio Flash Trigger AC-08A 6.35mm 1/4" Plug The item is the updated trigger of AC-04,It has new look,but 100% compatible with with DSLRKIT PT/DC/AC series flash trigger.(Except PT-16&PT-16NE) If you have an old DSLRKIT AC-04's receiver,it can work with the new 8 channels transmitter, or you can use your DSLRKIT 4 channels transmitter to trigger the new 8 channels receiver. 8 Channels, Max Sync Speed: 1/250 s, Operation Range:30m. Flash Connection 6.35mm(1/4 in) jack.