This is a pin and two tubes that will fit Omega Seamaster mid-size watch strap links.
These were not made by Omega but are high quality compatible parts that are made in the UK and designed to specifically fit the following Omega watch models-
2050.71.00, 2052.50.00, 2053.80.00, 2062.50.00, 2063.80.00, 212.30.36.20.01.001, 212.30.36.20.04.001, 212.30.36.61.01.001, 2222.80.00, 2223.80.00, 2250.50.00, 2250.80.00, 2260.50.00, 2260.80.00, 2401.10.00, 2401.11.00, 2401.16.99, 2401.20.00, 2401.21.00, 2401.26.99, 2401.31.00, 2401.50.00, 2401.80.00, 2401.81.00, 2401.86.99, 2403.20.00, 2411.10.00, 2411.11.00, 2411.21.00, 2411.81.00, 2452.20.00, 2452.80.00, 2462.20.00, 2462.80.00, 2501.21.00, 2501.31.00, 2501.33.00, 2501.43.00, 2501.51.00, 2501.53.00, 2501.81.00, 2501.82.00, 2501.83.00, 2506.80.00, 2508.80.00, 2511.21.00, 2511.31.00, 2511.33.00, 2511.43.00, 2511.53.00, 2511.81.00, 2511.82.00, 2511.83.00, 2514.30.00, 2514.50.00, 2521.81.00, 2551.80.00, 2552.20.00, 2552.80.00, 2554.80.00, 2561.80.00, 2562.20.00, 2562.80.00 and similar.
I have given you photos of your pin and tubes from every angle. Please use them to add to this description.
If you are not sure if this will fit your watch or if you have any other questions then message me. I'm here to help you.