Are you looking for CIB (Chicks in Bowls) or Brunny Blocks?  Slide Blocks work great at the skatepark or grinding on street curbs.  We have a ton of Skatepark Roller skate accessories including Brunny Hardcore Blocks, Disco Blox, CIB slide blocks, and Bont Slide Blocks.  And even blocks made out of recycled skateboards.