Classification is very important to gold recovery, and these Stackable Sifting Classifiers easy to use.Each size is 13.25 inch diameter so they are stackable on a bucket. Additional features and benefits: • Screen off large, worthless gravel and rock. • Size your material to the proper dimensions of the gold you are expecting to recover. • High quality stainless steel wire mesh is both accurate and durable for everyday use. • The plastic body is both lightweight and durable. • Resting the pans on top of each other takes up less space. • Differently sized mesh screens make classifying even faster. • Fits perfectly on top of a 5-gallon bucket. Use drop down menu to choose from 9 mesh sizes: Wire thickness: 0.10 mm—Mesh size: 1/100" Wire thickness: 0.14 mm—Mesh size: 1/70" Wire thickness: 0.17 mm—Mesh size: 1/50" Wire thickness: 0.30 mm—Mesh size: 1/30" Wire thickness: 0.35 mm—Mesh size: 1/20" Wire thickness: 0.45 mm—Mesh size: 1/12" Wire thickness: 0.60 mm—Mesh size: 1/8" Wire thickness: 1.40 mm—Mesh size: 1/2"