== Arm Cavity Finesse ==
We will change the transmission of the ITMs from 0.5% to 1.4% to match the new AdvLIGO design.

We will also replace the MOS (with 1.25 kg masses) with SOSs. This is to increase the effect of radiation pressure.

We will not fine-tune the coatings of the ITMs for cool dichroic properties unless some coating place gives us a <4 month lead time.

== Modulation Frequencies ==
We will change the modulation frequencies from f1=33 MHz and f2 = 166 MHz to f1 = 9 MHz and f2 = 45 MHz. We will increase the length of the MC to accomodate this.

== Recycling Cavities ==
We will increase the length of the RCs to handle the lower modulation frequency. This will require 2 tip/tilt mirrors per cavity. These will be imperial, eddy current damped versions of the ANU tip/tilt mirrors.

Should we get new PR and SR or use what we have? (curvature, reflectivity). Maybe we should match the AdvLIGO Gouy phases.

We will make the tip/tilts so that we can have a POP signal. We also keep POX & POY.

== Mach Zender ==
We will not use a Mach Zender. We will use 2-3 EOMs in series or a UF Trimod if it shows up.

== Control System Computers ==
We will have a big multi-core box to run all of the front ends. It will have fast fiber links to remote ADC/DACs.

== Multi-wavelength Locking ==
Make wedges and coatings to accomodate multi-color locking if the lead time is reasonable. The beam from the end should not see the corner.

== Optical Levers ==
Make a fiber based OL delivery scheme. Try to also make 40m long OLs by putting turning mirrors into the vacuum system.

== Analog Electronics ==

=== Suspensions ===
No change of the suspension analog electronics. We will have interface cards/connectors to go from new style ADC/DACs into the old analog electronics.

=== LSC ===
New RFPDs for the 9 & 45 MHz as well as 3*f1 (27 MHz). Maybe DD as well.

== Cameras ==
We'll have GigE cameras and an all GigE backbone for all CDS connections.