The Madbull Red is a softer bucking designed to work with the included Fishbone spacer to provide a bridge style hop up system. It's a very efficient setup without a need to flat hop or r-hop. This bucking also works great as a bucking to be flat hopped/r-hopped and with two included buckings if you mess up it's no problem ;)
Madbull is a well established brand ranging from internal to external parts all of very high standard! This bucking can fit tight in some setups so go slow on installation if you have issues getting the bucking into the chamber. Do NOT put oil in the bucking like the packaging says, some on the exterior to aid in installation is fine but on the inside will cause your gun to not hop BBs properly.