Worked as a replacement for a ULKA 2/1
Replaced worn out original Ulka vibrating pump on my La Spaziale S1 Vivaldi II.  The original pump was an Ulka 2/1.  That number is the duty cycle (on/off timing).  An Ulka 1/1; 1/1.5 will work fine if replacing the same or a 2/1.  That took a lot of web searching....  Happy with purchase. Would buy again.  Why 4 stars - well if 3 stars is average...and 5 is great; it works as advertised.  I gave it 4 stars because I was happy to receive the pump quickly. (Disregard the pulled pork).
Rating: 4 stars