DuraVent B-Vent Adjustable Elbows are used to offset the vent pipe to avoid any obstructions while maintaining the proper 1" clearance to combustibles. Available in either 45/60 degree and 90 degree angles. The 45/60 degree is able to adjust to any angle between straight up and down to a 45 degree angle. The 90 degree adjustable elbow is able to adjust to any angle between straight to 90 degrees. The DuraLock connection easily snaps to any standard length of DuraVent B-Vent pipe