These spring bars are made to replace the screw bars found in many Panerai Luminor models. If you have a Luminor and want to replace the screw bars with spring bars for easier strap changing, or find the screw threads are stripped and will no longer tighten properly, these are ideal. Please note – these spring bars are only suitable for Panerai Luminor watches using the screw bar strap attachment system. Each pack comprises of two spring bars.