I purchased both the type 1 and type 2. Took off both caps and pressed them into place. This way you have quick detach on both sides. It takes the shortest screw of 4 that came with the one you didn't buy. If you bought the 1, then buy the 2 and you are set. The reverse holds true as well, if you bought the 2, then buy the 1 and you are set. One was just a cup and a nut, not threaded.