For a Hirsch Curved End Watch Strap fitting guide, please see below:
Many people do not fully understand how these straps work and without having the strap in your hand, it can be hard to visualise it. What makes these straps great is their micro adjustment and universal fit, making them compatible with a lot of watch cases.
Concealed within the watch lug end of the strap is a small plastic insert which has two spring bar holes. It is this small piece of plastic that can be removed and rotated to adjust the spring bar position. You can now fine tune the spring bar position of the watch strap to suit the position of the spring bar holes on the lug of your watch. This may take a few attempts and some trial and error but once you have the position for one side of the strap, the other side should be the same.
Firstly, it is always good practice to tape up the lugs of your watch using masking tapes to prevent scratches when trying to fit any strap.
To remove the plastic insert from the strap, you will need to apply some force to slide it out using a Spring Bar Tool. We recommend sliding the insert out from left to right
Once you removed the plastic insert, you will see that it is numbered on the sides. We have included a key in the photos of this listing that shows the position of the lug holes when the plastic is inserted in that specific position. Reinstall the plastic insert by pushing it back in to the strap from right to left. Be sure that the insert is in just past the line of the leather otherwise this could mark the lugs of your watch. Then insert your spring bar into the correct slot and fit as normal.