WHAT DOES RM66 MEAN?

Also is the revolver six inch product drilled and tapped less than rear sight to be used having a purple dot mount adapter It seems like it’s about similar to the S&W 357 magnum revolvers with adjustable rear sightsProbably not. I'm an RM88 Smiley, RM07-03 Bon Bon kinda gal. This enjoy would've even afraid the 14-yr-old Edition of me who listened