The SB2 allows a CruzPro gauge (FU30/FU60, TL25/TL55, OP30/OP60, etc.) and one existing analog gauge to share a single station 10-180 ohm or 240 -33 ohm sender. Makes adding a digital gauge to an existing analog set-up very easy. One SB2 will buffer two separate senders (e.g. an oil pressure and water temperature sender, etc.).