MarXman Green is for holes up to 45mm. MarXman Black is for deeper holes over 45mm up to 100mm. The chalk is fluorescent and can easily be seen from a distance, particularly useful if fixing at height.
Marxman Marking Tool – Tools 4 Fools
GRIPIT MARXMAN GREEN OR BLACK CHALK MARKER PEN MARKING TOOL, STANDARD OR DEEP
GRIPIT: MARXMAN – Toolpro Distribution
Marxman Chalk Non- Permanent DIY Marking Tool Pen
GripIt Fixings MM488767 MarXman Standard Professional Green Marking Tool (Up To 45mm) - Atlas-Machinery
Marxman Chalk Non- Permanent DIY Marking Tool Pen Denmark
GripIt MarXmate Professional Green Spot Marking Tool - MARXMATE
Marxman Pen Set - 1 x Standard - 1 x Deep : : Stationery & Office Supplies
Gripit Marxman Green & Black Chalk Marker Pen Marking Tool Standard/Deep