Adjustment button with o-ring to assure tightness.

Redesigned pressure plate by adding an adjustment gear making accurate adjustment easier.

The Hardened the pressure pint making the hopper ore accurate and stable with faster pressurization.

Pressure Plates are interchangeable between raised pressure point type to the stock. Gives you two pressure plates for the price of one

Manual: http://jagprecision.com/media/wysiwyg/manuals/modify-metal-hop-up-chamber-manual.jpg