Bimba Pneumatic Model Number Question

[Vikesrock]

From the looks of the Bimba website the described cylinder would not be FRC legal.

MRS cylinders have an additional groove in the piston to accommodate a magnet. They differ from the Moption because they combine features of the "Z" line with Original Line construction. Type 303 stainless steel rods are standard.

Emphasis mine

This makes it sound like they differ in more than an "optional attachment part"

However, as Leav noted, the Q&A is the only source for a definitive answer.