This is everything needed to reseal SY accumulator control valves.  This is not for later SZ cars with throwaway spheres.  This kit includes all necessary EPDM o-rings, a new aluminum sealing disc and the aluminum washer for sealing the high-pressure adapter that connects the high-pressure line from the pump to the ACV. 
A new bleeder valve is included and a new ball housing that incorporates a fracture-resistant silicon-nitride ceramic ball that is orders of magnitude stronger than the original steel ball.  The original balls in the ball housings get a flat spot on them from years and thousands of cycles of being hit by the piston.  This flat spot can result in imperfect internal sealing.   Ceramic balls will never develop a flat spot.
A new Mainspring is included along with a new Non-Return Valve tip.
New  piston seals are included also.  These require a special tool to install which is available separately.  Look under the "Tools" tab.  Or click here.
For early cars with brake switches attached to the valve, new aluminum and steel sealing washers are included.
New mainsprings are available separately for $16. Just ask.