I will help out the seller a bit.
Flow as per manufacturer.
.200"
I 147 cfm
E 111 cfm
.300"
I 206 cfm
E 145 cfm
.400"
I 254 cfm
E 185 cfm
.500"
I 291 cfm
E 204 cfm
.600"
I 308 cfm
E 223 cfm
I've run these heads for a few years and they're great bang-for-the-buck.