The PA-A1 Eyebolt Kit is made specifically for your Mackie SRM450 or C300z loudspeaker. Suspending speakers is serious work that should only ever be done by certified, professional contractors - and they need qualified, professional mounting hardware to do the job right. Get the PA-A1 Eyebolt Kit for your SRM450 or C300z loudspeakers, and your contractors will thank you for having the right tools for the job on-hand.