Grade 5 (6AL-4V) titanium t-nut set. Each nut is 25mm long and has both M6 and M8 tapped holes. Includes 4 each M6 and M8 setscrews. The setscrews can be used to fix the t-nuts in the tracks. To avoid damage to your board, do not overtighten the setscrews!
Longer than a conventional t-nut, these should fit most boards without modification. A rectangular opening in the track that is at least 3/4" long will easily accommodate these nuts. Boards with a very small round opening in the track may not accept these track nuts because of their length. Please see pics for details.