The cymbal mounts on the uprights use 7/8"..there are no Alesis clamps available that size...but there are somecheap nylon ones on
ebay..next option is you can upgrade to a Gibraltar clamp.
The size differences also caused confusion with the STRIKE Kits as the original STRIKE/Pro (both discontinued) used the uprights (7/8")..the STRIKE Pro SE uses clamps (3/4").
The last 8 kits released by Alesis use clamps for the cymbals..only the Command Mesh and DM10 MKII Pro remain that are still using the upright for cymbals and are Chrome.(older rack generation). The latest generation of racks are back to black.
If you ever need or want to change/upgrade the upright cymbal mounts Gibraltar has a couple styles for using uprights that support multiple sizes but you would need to punch out the pins in the current black ones in order to replace.
EDIT:Added ebay link