I copy the following 2 paragraphs from another thread. Hope it helps.
I have Natural 1 in my 912c. Natural 1 is for small body (GC and GA) guitars. You can use Natural 2 for bigger guitars. I am very satisfied by the performance. The sound is acoustical clear. I plugged it in Ultrasound AG-50DS2. When the amp is set at the right setting for room size, the sound is so natural with only loudness to notice. The other good thing (although some said it is a bad thing) is that there is no control at the guitar. I just set the amp and play and play.
Fishman and other brands such as L.R. Baggs have many under saddle pickups to choose. You also can select the models with internal mic or soundhole pick up. There are a lot of products in the market. Fishman Matrix is a good one.