Purchased an Arrow Indy Race exhaust can for my 2020 Ninja 1000SX. Have not removed cat or expansion box, so the Arrow did not make much sound improvement with dB killer installed. Attempting to remove dB killer proved much more difficult than it should have been and I pretty much ruined the piece trying to get it unjammed from the exhaust. Contacted Arrow directly (Italy) and their U.S distributor about defective construction or improper dB killer tolerance since I couldn't budge it by conventional external means, including penetrating oil, multiple pliers, vice grips, etc. Finally got it removed at a shop that used the equivalent of a body shop dent puller that hooked onto the back side of the dB killer. After multiple pulls with the heavy sliding weight, it finally worked its way out. Turns out that the dB killer in my canister does not even look like what Arrow specifies in their ads, so I'm not sure what was going on with my particular unit's manufacturing as it was one of the very first units made for the 2020 Ninja 1000SX. Arrow completely blew me off and said they purposely install them this tight to prevent them from rattling inside the canister (?). Total BS and they completely lost credibility with me for their poor quality control and lousy customer support. At least it now sounds somewhat deeper and louder than stock and it definitely looks better than the oversized bazooka muffler that comes on this bike.