It is applicable to surface grinding & polishing of tombstones, slabs & mosaic that need to change the thickness frequently. Feature: 1. Guide surface on round column, no tiny vibration when lifts up and down 2. Vertical rocker arm structure & turing joint, wide working range available 3. Automatic & Manual elevating devices for customer''s choice 4. Single or Dual speed of main drive motor available 5. Worktable for grinding interior/exterior arcs available upon request[...]