We inspect for leaks, running toilets, working smoke alarms and carbon monoxide alarms, we check locks and fire extinguishers and make sure there are  no other conditions we might happen to see while there...like extra roommates and animals that aren't allowed in these particular units. 

Make sure the tenant changes the filter often.Landlord vs Tenant ResponsibilitiesYou're onlyresponsibility is to provide a safe, habitable property that is up to codeSmoke detectors,heat, appliances, plumbing are things you are responsible for If a tenant breaks something like a window, hire someone to fix it and charge the tenant Tenants responsibility to report problems or they will have to pay for itAnnual Preventative MaintenanceSpot problems beforethey become an issueGive the followinglist to a handyman once a year (interior): Change furnace filters Vacuum dust from fridge coils Replace smoke detector batteries Check carbon monoxide detector is working Sweep fireplace Ensure lint from the dryer vent has a clear path to outside Flush water heater Check the expiration date on fire extinguisher Repair broken caulk or grout in the bathroom Tighten any handles, knobs, racks etc.

Smoke detectors, carbon monoxide detectors, well-lit stairways and entries, timer switches on fireplaces, updated outlets in the bathrooms and kitchens to prevent electrocution, etc.   

As mentioned by Lien, the things they look for are screens in every window, smoke/carbon monoxide detector, safety issues.

One of which would be carbon pleated air filters.

I was in the process of evicting a tenant in Carbon County, PA.

You can check smoke alarms and carbon monoxide detectors, along with furnace filters.

Smoke detectors and carbon monoxide are required as well.  

I've been investing in SFRs and small (4-2 fam) multis in Edwardsville and Glen Carbon, IL.

If they can go the carbon fiber strip route to stabilize the bowing and seal the walls it’s not as expensive as a complete waterproofing.