The Pro-Jects tonearm philosophy normally uses stiff, one piece, mid to light weight designs with Cardan pin point bearing. This tonearms perform best with all MM cartridges and MC cartridges with middle compliance. They are responsible for our famous lively, fast and dynamic sound, even in lower price ranges. A unique counterweight construction allows you to balance cartridges from 5 up to 25 grams (excluding headshell) depending on weight of the chosen headshell (up to 37 grams with ´Alu´, up to 39 grams with ´Carbon´, up to 41 grams with ´Wood´). So, this is also an ideal tonearm for direct mounting of SPU cartridges. However the high-end analogue market has moved to a more classic design and use of relatively heavy cartridges with low compliance and low resonance frequency. This allows big sound on big systems. Such cartridges need a heavier arm with more internal damping. Additionally, many customers today want to use different cartridges with different sound types depending on the music style. For this you need a detachable headshell to ensure easy and quick changeovers.