The grip panel areas of the Gen3 RTF2 Glocks have small raised pyramid-shaped polymer projections, at a linear density of about 20 per inch (around 400 per square inch; gun is a Glock 17 Gen3 RTF2). The same areas of the Gen4 Glocks have larger, flat-topped pyramids at a linear density of about 12 per inch (approximately 144 per square inch; gun is a Glock 22 Gen4). In addition to the differing shape and densities of the pyramids, there is one more significant difference -- on the Gen3 RTF2 guns, the gripping pattern is extended into the thumb-rest area of the grip (see the photo in post #1 at the top of this thread for a side-by-side comparison of the two frames). While it may or may not be helpful in adding to the security of the shooter's grip, it has been the source of some complaints about an abrasive "sandpaper" effect on certain areas of the shooter's thumb, especially when expending large quantities of ammo in a short time (examples: competitions and Law Enforcement qualifications). Wanna kill these ads? We can help!