The Logan F300-3, or Logan Underpinner, is a new, professional-grade picture frame underpinner for quick, accurate joining of picture frames, the Logan v-nail joiner drives V-Nails up from under to join any size picture frame. The adjustable height allows the work surface to be leveled flush with a table top to support longer legs of moulding and the versatile clamping system allows for any width. The Logan F300-3 permits the stacking of V-Nails for deep penetration of extra thick mouldings. Uses Logan Magazine-Style V-Nails. Includes (800) 1/4″ hardwood V-Nails and 1/2″ medium/soft V-Nails. Recommended for use with the Logan Frame Gluing System.