Lowell Woods boat shuttles are crafted from hardwood maple and use 4 inch bobbins. The stainless steel pin allows free spinning of the bobbin and snaps into a groove in the shuttle. The smaller size is perfect for smaller shed floor and rigid heddle looms. Each shuttle is hand crafted by Eric Bartkus, a woodworker, mechanical engineer and weaver. Lowell Woods is new to Amazon but has produced and sold hundreds of this shuttle at Etsy and Ability Weavers. Every review has been 5 stars to date. Thank you for considering Lowell Woods.