I have a Grip Force Adapter that fits Glock Gens 1-4 Standard & Compact sizes.

per their site: GEN 123SC ADAPTER

Note that this adapter has been trimmed down on the textured grip part. I believe the previous owner did this to accomodate the subcompact Glocks. It is not meant to be used on the subcompact models per the company but it will mount and does work. I am not endorsing it to be mounted on the subcompact models, however. That would be up to the discretion of the purchaser. The adapter still works great. The price is $15 shipped. I accept PayPal & USPS Money Orders. Please ask any questions via PM. Thanks for looking!