The Mark III is a modified design incorporating a vertical inline lubricator which is filled from inside the cab using the syringe provided. This greater oil capacity increases the lubrication of the steam resulting in a more efficient engine with less wear. The fire box door is a cosmetic feature which can be removed to uncover the boiler certificate number. 
Dimensions: 230 × 100 × 120 mm.
Weight 1400 gms.
SPECIFICATIONS:
Overall size 230 mm
Overall width 100 mm
Overall height 120 mm
Weight 1.3 Kg
Boiler diameter 44 mm dia
Volume 1.8 cm³, 120 ml
Lubricator capacity 5 ml
Safety valve 40 psi 2.75 bar
Decal included in box
Cab sighted steam regulator