604 & HT604
The Invincible 600 has a built in solid steel ring locked in place by reinforcement materials at the arch crown. This enables the 600 to handle vacuum conditions in excess of those listed for the 500 in multiple arch joints.
The Invincible HT600 has all the construction features of the 600 combined with High Temperature capability. DuPont Kevlar® or other heat resistant fabrics replace the polyester or nylon. The tube and cover are either EPDM or Viton® for full vacuum service up to 350°F and 400°F respectively.