Active chainring spider reduces/eliminate feedback through pedals from pedal kickback and chain mass oscillation during descending. Makes a big difference to suspension action and control which allows you to ride faster! 

Pinkbike's Matt Beer says:

"The chain forces that the Active Spider isolates is quite impressive. I believe there is both a physical improvement to the suspension performance when the chainring can rotate to a degree, plus it adds a qualitative bonus by reducing the noises caused by chainslap. The small amount of lag in the pedal stroke is a tradeoff that is worth coming to terms with if the bike in question is susceptible to chain feedback."

Link to the Pinkbike review here 

Ochain for Hope direct mount cranks - Chainring bolts included

Main material: Al Alloy 7075 T6

Dimensions: 93 mm x 93 mm x 13 mm

Weight: 128 g

Chainline 52mm (Boost only)

Black hard anodized (Nero) or Nickel Chrome (Pregio)

Standard BCD 104 mm chainrings

Provided with Ochain Rubber Kit to switch from 6° to 12° setup

Ochain and chainrings fit only with 5mm length nuts!