This item was created by me using a 3D printer and handcrafting. It has been used successfully in actual fishing. Most of the plastic (PLA) is 3D printed, while the stainless steel eye and the spring for opening and closing the cage are handmade. Images 1-3: The mechanism is designed to open the cage simultaneously with water entry. It's designed to open the cage as easily as possible within a range that doesn't hinder fishing, so you don't waste time with the cage not opening. Also, the spring is designed not to bounce up excessively to prevent line entanglement. See images 4-5: There is a screw-on lid on the bottom cage, allowing you to insert weights of your choice. It can accommodate weights of a certain size. I put in a teardrop weight as is. Weights that don't fit can be shaped with a hammer without melting them. The weight is approximately 55-58g. See images 6-7: The concept is large capacity, and it feels like it holds more than twice the amount of chum as a commercially available Apollo Ippatsu Cage. The diameter is also large, about 5cm, making it very easy to put in chum. The cage diameter is about 4.3cm and the height is about 12cm. You can attract fish by scattering chum all at once with fewer casts. Assuming you put in horse mackerel, considering the fins and body of the horse mackerel bending, it should be able to hold small horse mackerel as well as tiny ones. It's also perfect for live bait fishing. See images 8-9: In one test fishing trip (about 3 hours), I caught two 45cm sea bream! ヾ(*´∀`*)ノ Image 10: This autumn's catch! Blue-backed fish and rockfish, they're biting! Please understand that this is handmade, so there may be individual differences. The weights and Apollo Ippatsu Cage shown in images 5-7 are not included.