This is a stainless steel Diff / Bevel box breather.

Suitable for many Boxer models fitted with this threaded hexagon ventilation cap including :

R45  R45T   R65   R65LS   R65T   R65GS   R65RT

R80  R80ST  R80RT  R80GS  R80G/S

R100CS  R100RS  R100RT  R100T  R100/7T

Supplied complete with new sealing washer.

Replacement for BMW Part number  33111238838