I was a buyer for a major home building products company. I purchased k-lux brick for that company, however I do believe K-lux brick went out of business back in the 80's. You can get the same type of product called Z-Brick. Ace carries it, also go to Zbrick.com, it will give you the retailers who carry the product. They also carry the mastic and sealer to install it.
Good luck, hope you find it!