Airmar makes most all of the transducers for the marine environment. Ditto our 1991 speed meter by Autohelm, now Raymarine.
Why do you want to remove it? I've found that if it is not working, I loosen the retainer enough to raise the transducer, wiggle it some to dislodge any marine growth and reset. That seems to work in most cases. If not, I have removed it completely, clean and replace it. As mentioned above, a bit disconcerting the first time.
I always apply some Desitin to the impeller blades before replacing to help keep marine life from growing.