This is for vertical installation of the Eccotemp 45HI (indoor models). You will need to purchase additional Z-Vent straight pipe. You will need to determine how many additional feet you will need as well determine if you will need a condensation drain. Also remember there is a maximum vent run of 20 feet, subtracting 4 feet for every 90 degree elbow in the run. Please also note that any vertical venting installation with more than a 5' run length requires a vertical condensation drain pipe as well. Includes: 1 x 4" Rain cap 1 x 4" Top support/Storm collar 1 x 4" Adjustable roof flashing (normal 30 degree flashing) 1 x 4" Universal appliance adaptor 1 x 4" Back flow preventor Z-Vent special gas vent kits are all made of AL-294C stainless steel and are category II/III and UL compliant.