Unit Heater vent kit for HD-30 thru HD-125, contains 1 each of the following items: 2ft pipe 4" single wall 26ga, 90 degree 4" adjustable elbow 26ga, 4" wall partition, 2ft B-vent pipe 4", 4" B-vent Top, 4-3 pipe reducer. for additional lenths, refer to the Furnace & Stove pipe catagory, B-vent, 4" or call us with your needs or questions.