Pin-Lock Knob - 1" - Consists of a 1/4"-20 female threaded security knob and key knob - Replaces all knobs on 1" diameter B size arms and mounts - Offers the ideal amount of leverage to properly tighten your mount to prevent slippage in heavy chop or in extreme vibration environments - Low in profile and only adds a small amount of additional bulk to your system when compared to the standard knob included - This additional peace of mind and tamper resistance comes at a very affordable price - The perfect accessory for keeping your mounted electronic device safe from theft and tampering