The Rain Maker Wind Maker Rain Wand is the industry standard
PLEASE NOTE: OUR OFFICES WILL BE CLOSED THURSDAY, SEPTEMBER 21ST THRU MONDAY SEPTEMBER 25TH
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.
Free ground shipping anywhere in continental US*!
*offer excludes orders to Alaska and Hawaii
Latest News

Booster Pumps and Water Pressure
Probably the most challenging problem on a water spray test site is achieving enough water pressure to properly run your equipment....
Read MorePass/Failure - The Definition of
“What do you mean, the window passes the water penetration test? It leaked water!” This is a complaint...
Read MoreSelecting the Test Procedure
There are a variety of water spray test standards between ASTM and AAMA, with other countries sometimes having their own standards....
Read More