The RM Group got started in 2004 on the strength of its flagship product, the patented Rain Maker spray rack. Located in Minnesota, we have our assembly center west of the Twin Cities in the old Tonka Toys building on the shores of Lake Minnetonka. Along with patenting and developing the Rain Maker spray rack, the RM Group continues to develop a variety of other products that enable testing professionals to adhere to industry standards for water and air infiltration testing. Our goal is to be a valued and trusted resource to the testing community, and to always provide the highest level of customer service. Our products are the industry standard when it comes to helping you perform water and air infiltration testing within the strict guidelines of ASTM, AAMA, WDMA and CSA.