No, they just sit inbetween the coil and the coil bucket. Same result as putting in a 2" taller spring.
Look online for a picture of one. Looks like a giant hockey puck with a hole in the middle.
So I installed the flux capacitor but the Jeep just won't do 88 mph.
-'99 WJ Limited, 4.7, Patriot Blue, 2" BB, 31" Mall-Terrains, Pavement Princess
-'97 TJ, Stone White, 4" Superlift, 33" SSRs, lunchboxed rear, 12K Titan winch, and 2.5 litres of exhillirating performance.