Above Amulet : Luang Phor Thuad amulet (made in B.E 2548) by Luang Phor Thong (Archan Thong) Wat ShamPoChey
below some sample of the common casing that we can found in the market.
Above Picture : SeMa Shape "Ah-Fok" (阿富盒) Casing
Above Picture : SeMa Shape Amulet Casing - Coated Gold (电镀金)
Above Picture : Amulets With Water Proved PVC Casing
My daughter's wearing : Tarkut B.E 2545 (pic left) by Archan Thong Wat ShamPoChey and Phra Luang Phor Thuad Amulet (right) B.E 2508 by Archan Tim Wat ChangHai
Above Picture : SeMa Shape Amulet by Luang Phor Thong (Archan Thong) Wat ShamPoChey