After 3 years of development and over 25 prototypes, Keene Engineering developed the perfect concentrator riffle. The first Hungarian riffle molded into a soft rubber mat is now included in many Keene products. See the amazing recovery of micro fine gold that this mat produces. Miracle Mat sits under the classifier screen that is placed at the head of the sluice box. Spot ultra fine gold easily and quickly by checking the Miracle Mat.
**ORDERING INSTRUCTIONS: Select the number of inches (25.4 mm) you need by entering that number in the Quantity field.