The Pearl Stop Lock for 7/8" Pipes is a tool to help get the height of your stands to be consistent and more permanent. These can be tightened with a drum key onto your stand to lock at a certain point to prevent the stand from going lower than that.
This is good for creating a consistent setup and ensuring old stands don't slip, but it can also be a great way to avoid having to replace stands that may have stripped lugs, preventing height adjustment. Throw one of these on there with a little bit of tape to prevent it from rotating, and a stripped stand can be used again, no problem.
This stop lock will fit on the following stand models:
CLH930, JG16, JG16NK, CH830, CH930, UX80, TH70I, TH70S, TH88I, TH88S, T930, T1030, TC930, TC1030