50x Approx Pairs M4 Slotted Cheesehead Bolts and Hexagonal Nuts.

Bolts have 6mm of thread.

Nuts are 6.9mm across flats.

M4 Threads.

May be used for Meccano Models as they are a nice fit in Meccano standard holes, but NOT the same as a standard Meccano thread.

Picture is an indication of what you will receive.