These are Brass Threaded Inserts from Du-Bro. FEATURES: Brass threaded inserts. The perfect way to put threads into wood & mount engines to wood mounting rails. Threaded inserts make a simple & effective way to make wing hold downs. These can be used where blind nuts are hard to fit. INCLUDES: (4) Threaded Inserts SPECS: Thread Size: 8-32 Length: 9mm kr3/17/03