XRAY Active Diff sections are CNC-machined from actually tough steel, whilst having really precisely-machined 'V' ramp grooves with 60° angle for effortless engagement/disengagement. The portion is hardened to make certain long life and durability. The portions are laser etched with "60°"" for simple and immediate recognition. Group of 2. The 60° portions provide an excellent balance of performance between on- and off-power. On-power the diff becomes hard after a delay. Off-power the diff becomes free after a delay. For use on low traction songs. Active Differential parts can be purchased in three various options: #352123 - 60° #352125 - 90° #352127 - 120° Active Differential Segments fit: #325100 - Active Differential for XB2/XT2/SCX #365100 - Active Differential for XB4/XT4 Font/Rear #365101 - Active Differential for XB4/XT4 Center"