XRAY Active Diff portions are CNC-machined from actually tough steel, whilst having acutely precisely-machined "V" ramp grooves with 90ð angle for simple engagement/disengagement. The component is hardened to ensure long life and durability. The portions are laser etched with "90°" for easy and simple instant recognition. Couple of 2. The 90° sections provide a very good security of performance between on- and off-power. On-power the diff becomes quite difficult after a quick delay. Off-power the diff becomes free after an immediate wait. To be used on medium traction tracks. Active Differential portions are available in three different options: #352123 - 60° #352125 - 90° #352127 - 120° Active Differential components fit: #325100 - Active Differential for XB2/XT2/SCX #365100 - Active Differential for XB4/XT4 Font/Rear #365101 - Active Differential for XB4/XT4 Center