LR Baggs M1A - Manual (Page 4)

3.2 Pickup installation: Be sure there’s a battery inserted into the
battery holder. Then plug the strapjack harness into the pickup.
Now loosen the clamp screws on either end of the pickup’s top
plate until the clamps are open enough to accommodate the
guitar’s top thickness. Then slide the pickup into the sound hole
and tighten the screws. Be sure to secure the wire with the two
self-stick wire clips provided so that it does not hit the inside of
the guitar during stage movement.
Tighten the screws snugly, but don’t overdo it -- this can damage
the pickup or guitar finish. If you are concerned about the
possibility of the M1 Active damaging the instrument’s finish,
consider applying thin cork pads (not included) between the
clamp and guitar. However, note that the clamps have been left
unpadded to improve coupling between the pickup and guitar
body. Because the M1 Active reads the top resonances that
provide depth and warmth, using cork pads may dampen this
sensitivity and adversely affect the pickup’s responsiveness.
4 . U S E R ‘ S G U I D E
4.1 Plugging in: The M1 Active will plug into practically anything
with good results. If you want EQ or use a direct box, our Para DI and
Venue DI provide both EQ and DI features. Plugging in turns
the circuit on and unplugging turns the circuit off. If you want
your battery to last a good long time, remember to unplug when
you’re done.