Delrin Advanced Forming Stake 0.25" for Synclastic Raising. Used for synclastic and anticlastic shaping. It is less expensive than steel stakes, the delrin gives full support while forming.The 0.25" (1/4" or 6.35mm) refers to the differences in the radii of each the curves in the stake. They progressively get larger by 0.25". The overall size of the stake is 9-1/2"L x 1"W x 1-1/2"H.The delrin mallets with cross peen are excellent choices to use with this stake.