There has been some talk here and abroad that the 50 sized Saito velocity stack is too small for the Saito 1.00 and the 1.25. It barely smaller than the 1.00's venturi ..015" smaller than the 1.25's venturi. I ordered some remnant K&S tubing both brass and aluminum and some 9mm pieces. The aluminum v-stack on the 1.00 is maybe .010" larger than the venturi and the V-stack on the 1.25 is about the same larger than the 1.25's venturi. The FA .40a is pictured because it has a cast in tapered velocity stack that 12mm deep. Just doin stuff for fun, naturally ruined a couple but no biggy, I just cut off some tubing and started over. To make the 1.25 V-stack I had to enlarge the hole in the V-stack clip,to .375".