Allgrip 304 Clout Nails 30 x 2.65mm, A2 Stainless Steel, Stainless Steel, supplied in a pack of 1000.
Clout nails have a large flat head that holds felt, slate, sheet and thin materials without pulling through. Galvanised or copper finish for outdoor and roofing use.
Drive with a hammer and leave the head flat against the material rather than sinking it.