For those of you who want to build your own sluice. One of the best materials I've found for both making Hungarian ripples and for helping hold down any miner's moss, ribbed carpeting or rubber ripples is to use aluminum carpet edging. It comes in various widths and lengths which is called either high or low profile edging depending on its width. By using it the normal way, it makes for a great Hungarian ripple ___/ and you can use either high or low profile edging to determine the height of your Hungarian ripple. I use a 1/4-20 hex-head bolt mounted in the center of my ripple, tightened down with washers and a wing nut on the under side of the sluice to both hold the ripple in place and any carpeting, miners moss or ribbing that is going to be held in under the lip of the Hungarian ripple. No doubt pop rivets could be used if you want to permanently want to mount it to a metal sluice. On the lower end of your miners moss, ribbed carpeting or rubber ripples you can reverse (turn over) your piece of aluminum edging and use it to hold your material down by once again drilling a hole in the middle of the edging and tightening it down with another 1/4-20 bolt, washers and wing nut. I usually cover any ribbing, moss or carpeting over with either 1/4" expanded metal or 1/4" sq. mesh for extra support between the pieces of edging and as an extra means to collect any fine gold, not to mention help classify the materials flowing over it. If you are using an exceptionally long piece of ribbing , carpeting or moss and it is bowing in the middle, mount a piece of 1/16"x 1/2" wide aluminum trim across the middle, mounted the same way as above to eliminate any bowing of materials.