Alnicov Bass Drum Pedal Kit with Spring & Tensioner - Heavy Duty Drum Set Accessory for Professional Drummers | Perfect for Live Performances, Studio Recording & Drum Practice

I have a DW 4000 double pedal. The 4000 series was discontinued in late 2000's, and the 2000 series basically replaced it. The 4000 series pedals do not have bearings on the rockers. I wanted to make my pedal to have less friction on the rocker, so I bought this to replace my "bearing-less" rockers.After installing these, I noticed my pedal requiring way less force to move, and the pedal moves freely even after I take my feet off the pedal. I always did maintenance on my pedals at least once a year, so my pedal was in great condition to begin with. But, this really made my pedal feel like a dw5000 in terms of smoothness, and agility.this basically turned a dw2000 into a dw5000. I had to slightly modify this with washers to actually make this fit tightly on my pedal, the top part of this rocker was just slightly too wide for my particular pedal. Its just how it is with my particular pedal. This bearing rocker almost looks just like the TAMA rockers to me, but I'm assuming this is a generic part for multiple brands of pedals.I highly recommend this to anyone looking to upgrade their pedals to make it feel like the "top of the line" pedal!