*PLUMBERSSTOCK EXPERT* responded:
Thank you for your interest in our Kohler K-7254-CP polished chrome industrial exposed shower. According to Kohler, there is no standard or maximum distance for the water supply inlet. Therefore, you may purchase the supply line with the necessary length needed for the installation. You may browse our website for a list of available supply lines. If you're ready to place an order, simply click on Add to Cart, enter your zip code and follow the succeeding steps. Thank you for visiting PlumbersStock.com!