The paper on top is a "Best Practices Update" from Broco.
Main points they stress:
1. Keep cable out of water when not welding - Prevents insulation breakdown from the "piezoelectric effect" which causes tiny holes in the cable.
2. No oil/grease on parts - Oil + oxygen can cause explosions with underwater welding gear.
3. Don't strike rod on stinger - Striking the rod on the stinger instead of the workpiece can damage the stinger jaws.
Work/Function:
1. Underwater electrode holder: Holds the welding rod/cutting rod and carries current from the surface machine down to you underwater.
2. Insulated for water: The red handle is special insulation made to prevent electric shock in water. Regular welding stingers aren't safe underwater.
3. Trigger grip: Opens/closes the jaw to change rods without taking gloves off