Dryer vent to exclude mice?

Is there a cage-type cover that will exclude mice? I have a couple vents where a Heartland won't fit. Wondering if 1/2 x 1/2 would be too much lint maintenance? I assume mice can get through 1 x 1/2 though I have held a few in my homemade swing panels with this mesh.

Mice and shrews around here would get through even 1/2 x 1/2. A decent quality flapper Is the best dryer vent in my experience. If you're looking for a retrofit, I don't know. But a vent is usually pretty easy to change out.

Try Fields Development, Should have what your looking for.

Fields Development and Supply- http://fieldsdevsupply.com/

Thanks. Just ordered one from Fields. I think our Peromyscus mice will be excluded by the half by half, at least most.

Just got my order. Great turn around time and craftsmanship on the cage covers. Will definitely be ordering from them again. Thanks for everyone's thoughts and assistance.