Swordfish 80030 - Plumb-Rite Bob Setter, 400g, 14 oz Consists of:
 
Adjustable hook for mounting on aluminium frames, nails or concrete
Powerful magnet for a firm hold on steel wall
Use flush pin to take 0 distance measurement or to hang cord immediately flush with upright surface
Safety bob cap protects bob tip and worker from injury
Stainless steel pin for attaching to wood surface