You are purchasing a Defender, Discovery 1 & Range Rover Classic Front Radius Arm Stainless Steel Fixing Kit
A4-80 is the equivalent of Mild Steel 8.8 high tensile bolts
Kits Consists of;
4no M16 A4-80 x 100mm Hex Head Bolts (BX116201L/RYG501550)
8no M16 A4 Flat Washers
4no M16 A4-80 Nylon Nuts (NV116047/NY116051L)
2no M20 A4 Flat Washers
2no M20 A4-80 Nylon Nuts (NY120046)

You have all the fixing to fit;
Radius Arm to Axle both sides
Radius Arm to Chassis both sides