This is the price for a set of 20. One item has been opened for photography. Purchased in February 2023, it has been stored indoors at home without being used. Mirai Kogyo High-Sealing Packing (for Detectors) 　Part Number: BZ-KCRS 　Standard: Round Coating ・Compatible with clean rooms and high-sealing properties ・For detectors with a screw pitch of 66.7mm ・Applicable alarm wire: 0.9mm, 1.2mm (20 pieces) If you would like to purchase individual items, please comment.