Gold/red is from an '04 ZX-6R (636) - same style as '04-'05 ZX-10R. Black/silver is from an '06 ZX-14 (same style as '06-'07 ZX-10R). Note the different bottom spring perches, adjuster, and obviously the reservoirs. They seem to be the same length - around 1/2" longer than factory 2nd-gen SV. For reference, the gold/red ZX-6R shock DOES require cutting the battery box and adding a spacer underneath the battery. The black/silver ZX-14 shock does NOT (just have to remove a plastic shield on front of the battery box via three Phillips-head screws).