B737 captain reported that during preflight check an improper tire was found to be installed.

Attributes
ACN	1664351
Time
Date	201906
Local Time Of Day	0601-1200
Place
Locale Reference	ZZZ.Airport
State Reference	US
Environment
Light	Daylight
Aircraft 1
Make Model Name	B737 Undifferentiated or Other Model
Operating Under FAR Part	Part 121
Flight Phase	Parked
Flight Plan	IFR
Component
Aircraft Component	Wheels/Tires/Brakes
Person 1
Function	Pilot Flying Captain
Qualification	Flight Crew Instrument Flight Crew Multiengine Flight Crew Air Transport Pilot (ATP)
Experience	Flight Crew Last 90 Days 144 Flight Crew Total 1799 Flight Crew Type 1799
Events
Anomaly	Aircraft Equipment Problem Less Severe Deviation - Procedural Published Material / Policy Deviation - Procedural Maintenance

Narrative:

Unbeknown to me; I flew a flight from ZZZ with an improper tire installed on my aircraft. I was scheduled to fly the same aircraft on the next leg and during the ETOPS (extended operations) pre departure service check the error was found and a new tire was installed.

Original NASA ASRS Text

Title: B737 Captain reported that during preflight check an improper tire was found to be installed.

Narrative: Unbeknown to me; I flew a flight from ZZZ with an improper tire installed on my aircraft. I was scheduled to fly the same aircraft on the next leg and during the ETOPS (Extended Operations) pre departure service check the error was found and a new tire was installed.

Data retrieved from NASA's ASRS site and automatically converted to unabbreviated mixed upper/lowercase text. This report is for informational purposes with no guarantee of accuracy. See NASA's ASRS site for official report.