You can also give him a binder. Binders come in wide varieties such as leather, nylon, etc. It is quite handy and in fact, essential for a working person. Another good option would be a business card holder that would make a nice promotion gift for husband. You can get it engraved with a personal message or a greeting.
If your husband likes to drink, you can give him a gift basket of specialty wine or beer. He would love to get such a wonderful gift from you and will appreciate your enthusiasm for his promotion. You could also give him gift baskets of other things filled with his favorite things. That would count for a nice promotion gift for husband.
If you want to go beyond the usual stuff, then you can throw a surprise party for your husband. All his near and dear ones could be invited to the celebration. It would make him immensely happy to see all his friends and family rooting for him in his accomplishment.
To make your husband look good at the workplace, a nice formal shirt would be a prudent selection as a promotion gift for husband. You can pick a shirt as per his taste.
A nice promotion gift for husband will be the channel that lets your husband know of your enthusiastic appreciation for and pride in him. A promotion gift for husband will only strengthen your bond with his & this is something that you would definitely look forward to.