This is a set of 10 head bolts, 10mm x 1.25 thread, for all DOHC Fiat and Lancia engines through 1982. R10.9 in strength, 17mm head.
Standard 17mm hex head. No need for special tools or sockets.
These are straight-torque bolts, not "torque to yield" taper-shank "stretch bolts".
Recommended straight-torque process in three steps: All bolts to 20ft-lbs then 40ft-lbs then 55ft-lbs.
Slightly different in grip length from factory OE bolt, but fully compatible for the application.
New and unused. (Re)build that engine with confidence!