This is a quick shoe clamp base plate from ULANZI. It's an Arca-Swiss compatible quick release plate with a 1/4" screw. I purchased it new. I am selling it because I no longer need it due to a review of my camera system. I will send the items shown in the photos. The following is a quote from the product description on the website at the time of purchase: ------------ 【F38 Quick Release System】: Note: This product is not interchangeable with Peak Design. Please be aware of this. The small quick release plate allows you to quickly switch multiple cameras to the same equipment. Or, the same camera can be quickly transferred between various different equipment such as tripods/monopods/stabilizers/sliders, which is a very convenient item. Quick release between the camera and tripod & head greatly reduces the effort of attaching and detaching. 【Arca-Swiss Compatible】: Both the quick release plate and the quick release clamp come with the Arca-Swiss 38mm standard, and can be set on the Arca-Swiss head side parts (clamp). Note: Only the F38 plate can be used on the base plate. Arca-Swiss tripods can be used below. 【Rich Expandability】: There is a 3/8 to 1/4 screw adapter at the bottom of the quick release set, making the expandability even richer. 【Safety & Security】: There is a slide block mode to prevent damage to the device due to accidental contact. The plate can be locked and unlocked by pulling and turning the side button. The product surface has non-slip silicone to prevent shifting. It protects your camera to the maximum. 【Reliable Quality】: The tripod quick release mount is made of high-precision CNC machined aluminum alloy, which is very lightweight and has strength comparable to duralumin, and also has good corrosion resistance. The load capacity is 15kg.