I am purchasing a lot of Selkirk materials for my new wood stove from Lowes. Lowes sells Selkirk supervent. When I go to selkirks web site I go to their supervent tab and look up lists of items such as DSP and look up the product number. For example I looked up the product number for a six inch piece of supervent DSP which is 266006. I type that product number into google and found some pretty cheap at walmart. Same product number, only thing is it is Metalbest. I have seen this on a number of occasions, I just want to make sure all the pieces I am buying are compatable.