Small L shaped key, 2 mm. Optional for repairs, as alternative to 1227.

Compatible met:
UltiMaker S7
UltiMaker S5 R2
UltiMaker S5 R1
UltiMaker S3
UltiMaker 3
UltiMaker 3 Extended
UltiMaker 2+ Connect
UltiMaker 2+
UltiMaker 2+ Extended
UltiMaker 2
UltiMaker 2 Extended
UltiMaker 2 Go
UltiMaker Original +
UltiMaker Original
UltiMaker Material Station
UltiMaker S5 Air ManagerM S5
Ultimaker 2+ Connect Air Manager
Ultimaker General Products