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  • Rain Maker Spray Rack
    Our Flagship Product
    Rain Maker Spray Rack
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Developing a variety of products & training that enable testing professionals to adhere to industry standards.

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Rain Maker Wind Maker Rain Wand
is the industry standard

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.

PLEASE NOTE:  We continue to be impacted by COVID-19 related delays to our supply chain. Delivery times may be longer than usual, and expedited shipping options may not be available.

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

Water Pressure & Booster Pumps

Probably the most challenging problem on a water spray test site is achieving enough water pressure to properly run your equipment....

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Pass/Failure - The Definition of

“What do you mean, the window passes the water penetration test? It leaked water!” This is a complaint...

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Selecting the Test Procedure

There are a variety of water spray test standards between ASTM and AAMA, with other countries sometimes having their own standards....

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