As per our long standing policy of not permitting medical advice on the forum - all threads concerning the Coronavirus will be locked.
For more info on the coronavirus please see the link below:
They are really great, but there is a short learning curve IMO if you aren’t used to a wider conical chamber, and the draft hole is smaller. Mine were all beaters from eBay, except the one above which was in remarkable good shape.
Kirsten sells replacement stems, but they are a bit on the pricier side IIRC, but well worth it to me.