the JFIT. Equipment Standing Boxing Bag has 3mm thick anti-rust steel plate includes 12 suction cups to stop base movement (Works only on smooth marble/tile/wooden floors). PVC bag can be filled with sand and water bottles to make the center of gravity of the heavy bag with stand more stable. Our Standing Boxing Bag can be placed at home, garage, tool room or gym. Well made, JFIT. Equipment Standing Boxing Bag made of durable canvas, foam sponge layer can slow down the impact when you hit and kick the boxing bag. Stainless steel pipe connects punching bag and stand base.