# OH3.4: changing UoM of existing items

**URL:** <https://community.openhab.org/t/oh3-4-changing-uom-of-existing-items/142872>\
**Category:** Items & Sitemaps\
**Tags:** uom, openhab3\
**Created:** [January 3, 2023, 9:41am UTC](https://community.openhab.org/t/oh3-4-changing-uom-of-existing-items/142872 "2023-01-03T09:41:01Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![binderth](https://community.openhab.org/user_avatar/community.openhab.org/binderth/32/56257_2.png) [@binderth](https://community.openhab.org/u/binderth)\
**Post date:** [January 3, 2023, 9:41am UTC](https://community.openhab.org/t/oh3-4-changing-uom-of-existing-items/142872/1 "2023-01-03T09:41:01Z")

</div>

I updated to OH3.4 yesterday.

I had items, which had `Number:Volume` as item type. They were linked with MQTT-channels, the MQTT-payload for it is 0…100. Apparently `Number:Volume` wasn’t intended for “humidity” and `litre` aren’t the correct unit for it.  
So I changed it to `Number:Dimensionless` and added `%.1f %%` as state description - but the values are not presented in `0.6 %` instead of `64.0 %`.  
Persistence used `0.64` as value in OH3.3 and the same in OH3.4.

So how can I get to `64.0 %` for those items?