... mm): 438, 542,613,6133) Water tank diameter(mm): 520, 620,710,7104)Material of inner tank: BTC340RWith porcelain enamel5)Material and thickness ... of shell:galvanized sheet 0.5mm6) Thickness of inner tank(mm): 2.0 ... , 2.0, 2.5,2.57) Thickness of insulating layer(mm): 40 ...