You are looking at a Thermal Detonator from Star Wars Episode IX. This particular detonator was on one of the Knights of Ren chest. It is marked #2 and it is incredibly unique because it was shaped at an angle that allowed it to set on his chest in a uniformed manned.
If you look at the picture of the bottom you can see the hole used to screw this into the suit. The Knight that used these detonators is Ushar.The display is a piece of sandstone that gives it that desert look just like the Knights in episode IX. It also has a very nice metal plate that describes the piece. It is definitely from the production of the movie. The item "Star Wars IV Screen Used Thermal Detonator, Knights of Ren Ushar" is in sale since Tuesday, May 4, 2021. This item is in the category "Entertainment Memorabilia\Movie Memorabilia\Props\Originals".
The seller is "bigscreenprops" and is located in Evansville, Indiana. This item can be shipped to United States, United Kingdom, Denmark, Romania, Slovakia, Bulgaria, Czech republic, Finland, Hungary, Latvia, Lithuania, Malta, Estonia, Australia, Greece, Portugal, Cyprus, Slovenia, Japan, China, Sweden, South Korea, Indonesia, South africa, Thailand, Belgium, France, Hong Kong, Ireland, Netherlands, Poland, Spain, Italy, Germany, Austria, Bahamas, Israel, Mexico, New Zealand, Singapore, Switzerland, Norway, Saudi arabia, Ukraine, United arab emirates, Qatar, Bahrain, Croatia, Malaysia, Brazil, Chile, Colombia, Panama, Jamaica, Barbados, Bangladesh, Bermuda, Brunei darussalam, Bolivia, Ecuador, Egypt, French guiana, Guernsey, Gibraltar, Guadeloupe, Iceland, Jersey, Jordan, Cambodia, Cayman islands, Liechtenstein, Sri lanka, Luxembourg, Monaco, Macao, Martinique, Maldives, Nicaragua, Oman, Peru, Pakistan, Paraguay, Reunion, Viet nam, Uruguay.