This is a good product for AEGs that meet two conditions.
1. They are low velocity/energy output as this is a very soft bucking and prone to ripping
2. No matter what you have tried, your AEG will not give any decent amount of hop up
In low fps (350fps and under), this will add hop up to any hop up unit that you want to tear your hair out because it will not achieve hop up no matter what you try. The reason for this is the little indent on the inside of this hop up rubber is actually much larger than normal and thus applies far more hop up than any other hop up rubber out there! This is why so many people have issues, its because they are essentially trying to add hop up to a unit that doesn't need any more pressure and thus cause jams, misfeeds, or over-hopping.
A prime example is the replica I used this in (an older CA M15) that had only 320fps and no hop up no matter what I did. Eventually I purchased this and after installation it instantly boasted my range far beyond what it was before.
-Great for setups which have no hop up normally and need a lot of pressure
-Doesn't work well in normal hop up units
-Tears easily when too much hop up is applied or velocities over 350fps w/.2 bbs
Rating: [4 of 5 Stars!]