Blade trip springs. Fits both Meyer and Western Plows.

They use this on a majority of their snow plows including:

• All ST series blades: ST-6 (ST-72) , ST-6.5 (ST-78) , ST-7 (ST-84), ST-7.5 ST-90)
• All STP series blades: STP-7, STP-7.5
• C series: C-7.5, C-8, C-8.5, C-9
• HM-9, HM-10, HMP-9, HMP-10
• Meyer Xpress plows with AG blades The New Lot Pro plows
  
• The Diamond Aggressor blades DAG