In my opinion Kadee couplers are a must for g scale garden railroads for reliable smooth operations. The 906 G scale type E couplers are a 10 minute upgrade on the AMS 1:20.3 coaches, combines and Long Caboose. The 906’s stand out in my opinion because they have a built in draft gear that in my opinion is pretty cool. They won’t fit all G scale equipment but so far I’ve used them on the AMS passenger coaches and the AMS Long Caboose and they work great. I use Kadee couplers on all my equipment.