Hello all I carry a glock 27 and just bought some used additional mags. First thing I noticed was that the followers on these mags say 5 on them and look noticeably different then the mags that came with my firearm which say 8 on them. So whats the deal with apparently different generations of mags? Just cosmetic? Function? Both? Either way these mags seem to cycle and lock the slide back just fine, still my curiosity is deff. peaked.