The gicleur is cheap to buy and easily availableā¦It is available in various sizes, for yours it depends on the pin size. A usual size is 7mm, but it could be 6, you need to accurately measure the diameter of the pin or see if itās printed on the top of the gicleur.
They are only brass and definitely donāt need to be screwed in very tightlyā¦.
P.S. You could ask Lelit and they will probably happily give you the jet size you need to order
