For my JL F1 F5024,I need to change the: 1.leather strap 2.glass surface(front cover)

Most of the people are pretty sure that when their watch leather straps are worn out they have to replace them with new ones, made by exactly the same brand as their watch brand is. This is completely wrong. About 95% of all watch brand models can be fitted with leather straps from any watch strap producer without loosing brands identity. All you have to do is: 1. Release the strap from the watch; 2. Measure the width of the strap where the spring bar (pin) goes through and write it down or memorize it; 3. Undo the buckle/clasp; 4. Measure the width of strap in place where the buckle/clasp was fitted and write it down or memorize it; 5. Measure the length of the strap (both parts together) and write it down or memorize it. Now you have everything you need for strap replacement. Visit any shop selling leather straps or even find it on the internet. You will find thousands of different colours, patterns and leather variations. The choice is yours. Just one thing to remember: The strap you are buying must match all the measurements you took of your original strap. This is not difficult to match, as the watch straps usually are made to global standards. When you have your new strap delivered, just fit it to your watch and undo the buckle/clasp that came with it. Fit your old, original buckle/clasp on to the new strap and you are done. Most watch manufacturers impress, engrave or laser engrave their logos on buckles/clasps, not on the leather straps itself. So, when you fit the original buckle/clasp on brand new strap of different make, it becomes the original strap of the watch you own. And nobody knows that the strap is, for example, from Hong Kong, but watch is from Switzerland (except you, of course} as they look together as one nicely designed piece and the buckle/clasp works as the proof of identity. In case if your watch has some unusually shaped fixing for the strap, this shape can be easily cut in to the strap by modellers scalpel. At the very end I just want to remind to all readers: Watch straps sold under watch brand names are 2-10 times more expensive. In fact - they are not produced by watch manufacturers themselves, but in Italy, Germany, China and Hong Kong and then sent to watch manufacturers. Just because these straps were fitted to the watches and the buckles or clasps were added to them, these straps automatically becomes their brand straps and cost a lot, lot more. Hope it helps to save your hard earned money.