roller ball (1) Size(meters): 2.6 ~ 3.5m,all as per ... ; (2) Material: polyether TPU 0.7mm or PVC plastic roller ball Specifications for zorb balls,grass walking balls,water balls,water ... , PVC or TPU Material note: steel(zinc-plate, 430 stainless iron, 304 stainless steel) 304 stainless steel is appropriate for sea ...