These cylinders are now being offered in partnership with R&R Model Engineering. These units are an excellent choice for larger models, and offer the added flexibility and features available from true twin tank ballast setup. Properly set up, individual control over each tank is possible for precised control of not only buoyancy, but overall model trim as well.

Features: 
Polycarbonate tubing throughout
Pressure Cast polyester end caps 
Main cylinder 100mm Dia x 500mm Long.
Ballast Tanks x2 70mm dia x 150mm Long 
Each tank holds 1/2 litre of water giving 1 litre total.
Total Displacement Surfaced 3.9kg
Total Displacement Submerged 2.9kg 
X One 540 Motor Single Shaft Version
X Two 385 Motors Twin Shaft Version
3 Metal Geared Servos for Rudder and Dive Planes
 
3 Pushrods with  Kwik Klip Magnetic Connector
2 Water Pumps
10 plug in terminal blocks for wiring and servo connection
On / Off push button switch
 
The Nautilus Drydocks variant of this product differs from the standard offering from R&R in that we include the following over the standard unit:
 
Electronic Speed Controllers for both water pumps and main drive motors
Full pre-wire with all connections and wire runs installed
AD2 electronic pitch controller
Full function test and waterproof integrity check
Just install your radio receiver, install your battery, and you're done!
 
Please allow 4 to 6 weeks for fabrication, assembly and testing of these cylinders.