Simple manufacturing method of manual dumbbell

1. We cut off about one third of the top and bottom of the beverage bottle with a knife, and then put the cut two parts together again. 2. The connection positions of plastic bottles are wrapped with transparent glue and insulating glue, and each dumbbell needs two such bottles. 3. Cut down the wooden pole and use it as the handle of the dumbbell. 4. Prepare a yellow paper funnel and pour sand into the bottle through the funnel.