There have been many versions of the Max-Flo regs since they were first introduced in 1998. Here are some pictures and information about each.
Max-Flo manifold: (2000-2003)
This is the most commonly-seen version of the manifold regulators. This was available in 4500 style (for HPA only), or 3000 style for a period of time, which accepted CO2 or HPA. Tank systems available in HP or LP output.
A screw-in version of this reg came on Shocker Sports as well as Impulses until 2003. This was designed to be used with a gas-thru grip, since it regulated down to 200-psi levels.
Max-Flo manifold (old-style): (1998-2000)
This was the original version regulator system. These are less common nowadays, but can still be seen. These perform relatively the same as the later versions of the manifold regulator. They were available in 4500 versions in 2000, and screw-in versions from 1998-2000.
Max-Flo Inline (MF-I): (2003-2005)
The Inline Max-Flo was the first main redesign of the reg system, coming into late 2003. It is essentially the same as the previous regulator, except with a different layout of parts and smaller arrangement. This reg was discontinued when the Micro system was released.
Available in HP primarily. LP output versions were also made ,although they didn't come on any markers so there aren't too many floating around.
Max-Flo Micro preset: (2006+)
This is the current version regulator system. This reg is designed completely differently and is much smaller as a result. This system isn't adjustable like the previous regs (output is approx 800-psi, varying from reg to reg).
High/Low Pressure Output:
The adjustable regulator systems (Manifold and Inline) were all available in LP and HP output versions. Countrary to common belief, you need to change more than just the output spring to change the pressure. To convert the pressure range, you also need a new regulator piston and a new reg body (to fit the new piston), plus the new adjustment spring. Conversion kits were once available but aren't any longer since the regs were discontinued.
If you purchased a manifold or Inline system and need to find out which pressure range it was made for, use this picture for guidance:
The adjustment springs themselves are more difficult to tell from one-another, but there are small differences. The below picture applies only to the manifold version.
