Honeywell HR 40 Installation And Operating Instructions Manual page 6

The Honeywell-Braukmann, MNG, Heimeier, Junkers, Landis & Gyr 'Duogyr'
valves do not require an adapter. Adapters are available for Oventrop, Herz,
Danfoss and Vaillant valves:
RAV (grey)
5
Adapter manufacturer/type
Oventrop HU 01
(knurled nut M30x1)
Herz HU 02
(knurled nut M28)
Danfoss adapter set
EVA 1-Danfoss
RA (white) (enclosed)
Vaillant adapter EHA 1VAI
Order No.
073341076
073341725
072031201
RAVL (black)
072031082