Water cooled beam tube length 15 mm
https://indus.ms-engi.com/shop/p-10032-water-cooled-beam-tube-length-15-mm-112
https://indus.ms-engi.com/web/image/product.template/112/image_1920?unique=119eb4b
Water cooled beam tube with below - diam.: 50 mm - length: 15 mm
