Howe also lists the Charlynn valve as a 3 turn version. This is the 3 turn x 8. Howe describes slow input steering for rock crawling as about 1 1/2 turns lock to lock, so tell us about your build if you're deciding between 2 and 3 turn.
A Charlynn valve is what steers a full hydraulic system: you turn the wheel and the valve meters fluid to the ram.
Howe Performance part number 827.