YOU ARE BUYING A BRAND NEW REPLACEMENT FOLLOWER BUSHING SPRING ASSEMBLY. PART NUMBER IS 900520. THIS IS THE SPRING FOR THE IM350 PLUS MAGAZINE. PLEASE NOTE THIS IS NOT AN ORIGINAL PASLODE PART BUT DOES THE SAME JOB, AND IS THE SAME QUALITY AS THE ORIGINAL PART. YOU ALSO GET THE ALLEN KEY THAT ENABLES YOU TO OPEN YOUR TOOL TO REPLACE THE PART. QUIKLOAD PEN SUPPLIED WITH EVERY SPRING BOUGHT.