For light weight gold recovery nothing beats the Tee Dee E-Z Sluice. At 24" long, 2.5" deep and 7" wide, the E-Z Sluice will fit in most packs and weighs less than 2 lbs!
The box is molded of polypropylene plastic with two sets of ABS riffles over Nomad (miner's moss). Most of the exposed surface area of the box is ribbed for further gold catching. Riffles snap in and out for easy clean up.
Add the optional flare (requires drill) and you have all the performance of a larger sluice box in a compact and light weight package.