Because it's made to the ORIGINAL SPECS from 1985.Thanks! Sir, if I may ask, why is the Mann trem arm shorter than the import?

BTW... we just released a US version of the ORIGINAL SE Arm . 1" longer than the Core or MannMade USA arm, with or without arm tip - https://store.guitarvaultusa.com/MannMade_USA_Vibrato_Bridge_Arm_p/5061.htm
This arm only fits PRS Core or MannMade USA bridges.
(It will NOT fit PRS SE/S2/CE factory bridges)