The Maple Leaf  Macaron Hop Up Rubber 70° for AEG is specially designed for use in AEG (Electric) Airsoft replicas. The special feature of this bucking from Maple Leaf is that he is on the standard bridged barrels, but also the non bridged barrel can be used what you as a user a wider option of barrel choice gives. The number of degrees say…
The Maple Leaf  Macaron Hop Up Rubber 70° for AEG is specially designed for use in AEG (Electric) Airsoft replicas.
The special feature of this bucking from Maple Leaf is that he is on the standard bridged barrels, but also the non bridged barrel can be used what you as a user a wider option of barrel choice gives.
The number of degrees says something about the hardness of the rubber. 50 Degrees is the softest variant and 80 degrees the hardest variant. The different hardnesses can be used in different ways in your AEG.
It makes no sense to use the hardest bucking when it is around freezing point because the cold makes a bucking stiffer and therefore harder to adjust. It is precisely in cold temperatures that you want a softer bucking.
The hardness of the bucking is also linked to the weight of the bb you are playing with. You can easily use a 0.30gr bb on a 50 degree bucking but this will probably result in it needing to be replaced sooner than when using this weight on a 70 degree bucking.
In the end, it comes down to personal preference.