If your man loves to challenge his brain and likes to get his hands dirty, you may consider buying him a model plane or car. There are a variety of both vintage and modern model planes available in the market.
If he’s particularly interested in the model you buy, he’ll be excited about constructing it and showing it off to you and the rest of the world. On the other hand, if you think puzzles are more of his thing then get him a 1000+ piece box that tests his brain and that he can feel proud to complete.
Because a lot of precise attention is needed for both these activities, your partner will appreciate the thought you’ve put into the gift.