WR and Early KR Valve Springs. They will also work on WL & G engines. I have a very limited supply, when they are gone thats it. S&S doesn't have plans on having more made.
This is straight from the S&S catalog. 
WR 45" and early single spring equipped KR- Designed for best results for cams with up to .450" lift. Use with stock collars and other valve train components, installed height of 1.970" yeilds valve spring seat pressure of about 92 lbs. ( add approximately 28 lbs / .100" of lift to calculate pressure at maximum lift), coil bind height is 1.375" (HD#18200-32)  
Note: The greater seat pressure generated with these springs may cause additional wear on flat tappet valve train components. If less seat pressure is desired, the installed height may be increased accordingly. 
Set includes 4 valve springs only. 90-2345
Product Price $100
Shipping in the U.S.A $10