Apex wash a matic???

[Compwhiz]

I have a question about the apex wash a matic

How does it create the wash action???

and here is a stero slide of it sadly they are out of stock

http://www.3dstereo.com/Merchant2/merchant.mvc?Screen=PROD&Product_Code=CSS-wash10&Category_Code=SSLIDES&Product_Count=0