Are you looking for some smaller priced gifts, or one big/expensive thing?
Some of the smaller things I got for my DH that he's loved are:
Books
An endoscopy camera (not as weird as it sounds!), it connects to his phone via an App and he can use it to look in the inner workings of his car/motorbikes when he inevitably drops a tiny screw or bulb inside. From Amazon.
A USB chargeable cordless handheld car vacuum. Really neat, again from Amazon.
A little Gerber multi tool that fits on to his keyring.
A selection of 10 Japanese KitKats. Their KitKats are very small and are in really interesting flavours. From eBay.
For an expensive thing, the most recent was a few years ago and it was a new jacket for his motorbiking. Obviously that wasn't a surprise and we had to go into the shop to choose that. Prior to that it was probably a pair of Barbour boots that I knew he'd looked at but wouldn't spend the money on.
If you give a bit more information on what your DH likes to do (gardening? hill walking?) I'm sure others will be along with suggestions.