Product: Superior 18-1201 Spring-Lox,2-Way Adjustable Spring Spacer
Overall sentiment: positive
Customer reviews:
Gr8 Product Will recommend to any buyer, had this installed on my Nissan Skyline to add a little height to the back, very impressed with it, easy to install and you can adjust height to suit your taste, just jack up your vehicle install. 
 Great item and super fast shipping 
 Excellent 
 Verry good Item 
 Worked ok 
 works great 
 okay 
 works good for a temporary fix. leveled my ride back to factory specs. 
 not the smartest way to lower your car... but i cant blame the product for my use for it... held up well under abuse. very well constucted 
 Great deal, fast service 
 Product does what it is advertised to do. 
 good product and a good price! 
 Great quality and fast 
 good 
 didn't use them but they seem well constructed and built to last 
 good 
 this item was alright. but the bolts was about a half inch to short. so I have to go and get me longer bolts. 
 Works as intended, lifted rear coil spring. Does not seem to move around coil spring, stays where you put it. Kit comes with 2 spacers, some kits come with 4 but are twice as much. 
 bought this for my 2005 van, driver rear coil spring was a little soft/sagging, fit this in and adjusted and works great, no more bottoming out over bumps in road. 
 I like the construction on these.  Sturdy, yet not so heavy they are cumbersome.  Super-easy to install.  Use two per spring so they balance the spring. 
 I needed these to use as an adjustable wedge on a sliding bookshelf (and not as a spring compressor or spreader) so these worked excellent for my needs. Just as a heads up, you will need two 14mm wrenches whenever you use these spring-lox. 
 Excellent quality, works perfect