So many replies discuss completely different and unrelated anomalies.  As if some magic box will solve all.  As if a recommendation without numbers can be honest.

  For example, normal voltage for electronics is even when incandescent bulbs dim to 50% intensity.  How often are your bulbs dimming that much?  Why then do so many recommend AVR or UPS for low voltage?  Advertising and hearsay says so - subjectively.  Well, here is a relevant number.  How often are your bulbs dimming that much?  Zero times?  Then best AVR is standard inside all electronics.

  How many joules does that Cal-Lab or Belkin absorb?  A thousand?  Destructive surges are hundreds of thousands of joules.  What will the Belkin et al protect from?  Surges that are already made irrelevant by existing protection.

  One concern is a rare transient that can overwhelm existing protection inside appliances.  What will absorb hundreds of thosuands of joules?  What makes even direct lightning strikes irrelevant?  Earth ground.

  A lightning strike far down the street is a direct strike incoming to all appliances.  Are all appliances damaged?  Of course not.  For reasons taught in elementary school science.  To have damage means a current must be incoming on one path.  And simultaneously outgoing to earth on another path.  What is damaged?  An appliance that best connects a surge to earth.  Not a receptacle's safety ground - earth.

  What is found in every facility that cannot have damage?  Protectors distant from electronics.  And always a connection low impedance (ie 'less than 3 meters') to earth ground.  For cable TV, that connection is best made by a wire - no protector.  Neither telephone nor AC electric can be connected directly to earth.  So we use a next best thing to make that low impedance (ie 'less than 3 meter) connection:  a 'whole house' protector.

  Remember an important number.  A surge, that can overwhelm protection already inside appliances, can be hundreds of thousands of joules.  What harmlessly absorbs that energy?  Single point earth ground.  All four words have major significance. Even the length of that wire to earth is critical - even a sharp wire bend compromises that connection.

  Neither Cal-Lab, AVR, Belkin, etc claim to protect from typically destructive surges. As demonstrated by manufacturer specification numbers that recommend each device. 

  Do this.  Ask only about one anomaly. And always demand spec numbers.  Nothing protects from all anomalies.  Voltage regulation is a concern when light bulbs dim to less than 50% intensity.  And then an entire post longer than this one can discuss effective solutions unique to that anomaly.

Noise is another concern.  A completely different solution addresses that.

Belkin is for a type of surge already made irrelevant by what is inside all appliances.

Lightning is another type of surge that the Belkin does not even claim to avert.  Don't take my word for it.  Every recommendation either provided relevant manufacturer specification numbsrs.  Or is best considered bogus hearsay. A discussion of that anomaly can also be longer than this post.

Which anomaly concerns you.  Ask about each separately.  Only then can effective solutions be suggested ... with manufacturer specifications that say how good.  BTW, best warranties are more often found on lesser products.