Many modern faucets have pull out hoses to combine the function of faucet and sprayer into one appliance instead of having a faucet and separate sprayer for rinsing dishes. To assist in the retraction of the hose into the body of the faucet many faucet manufacturers place a weight on the hose. This also assists in holding the head of the faucet in the body particularly the goose neck faucets where the heads are pointed down.
The weights have several issues. If the weights are mounted to the hose, as most are, the 
hose can only be pulled half way out before the weight hits the body. When the hose is retracted the weights often bang on the plumbing. If a boxes are stored under the sink the weight will hit the box which will stop the weight from helping with the retraction.
Eclipse faucets come with a spring retraction system. With the spring retraction system the hose can be pulled out farther so more of the hose can be utilized. There are no weights to bang on the plumbing. The spring will work even if there are boxes under the sink.
The spring retraction system including spring and spring holder (see insert) provide a superior retraction system.
