This remote pressure switch is designed for the WF-501B flashlight. It allows you to control your torch remotely. Function: Remote Pressure Switch Compatibility: - WF-501B LED Flashlight - Flashlights with a similar metal case design Size: 3cm x 2cm x 2cm (1.18in x 0.78in x 0.78in) Diameter of Remote Pressure Switch: 23.5mm Material: Aluminum, plastic Color: Black Note: Before purchasing, please confirm that this switch is compatible with your flashlight model, as variations may exist in the market. Package includes: 1 x Remote pressure switch for 501B (Other accessories not included) Note: Lighting effects and display differences may cause slight variations in color between the image and the actual item. Measurement error allowed is +/- 1-3cm.