MakerBeam M3 , 6mm hexagon head bolts fasten beams to other MakerBeam XL elements such as brackets and bearings. Contents: bag of approximately 100 M3 hexagon head bolts (6mm). Used for MakerBeam XL (15mmx15mm). Compatible with OpenBeam. Application: scientific, electronics, laboratories, home technical projects, displays/exhibits, robotics, etc. MakerBeam (XL) is a versatile and lightweight structural system (T-slot) with components that give endless building possibilities in desktop size. There are no fixed positions for mounting giving you the freedom to build your own design easily. All MakerBeam XL elements can be combined and reused (no welding required) enabling shorter design and assembly times.