最初のふたつは接着剤流し込み
あとのふたつは金属圧着かな
https://jp.xhamster.com/videos/permanent-chastity-xho1clH
https://jp.xhamster.com/videos/chastity-permanently-locked-xhTJRqz
https://jp.xhamster.com/videos/permanent-locking-chastity-12017024
https://jp.xhamster.com/videos/sub-rivited-in-chastity-13151428