A zinc pencil anode that is Caterpillar original part number 116-7011 with 1/4"UNC thread. 

The pencil anode is manufactured to US MIL Spec by Tecnoseal in Italy, one of the world's leading suppliers of sacrificial anodes for cathodic protection in the leisure boat market. Every zinc anode sold by Anode Outlet is genuine and manufactured to the highest quality anode specification. Item(s) shown in image may not come in manufacturers’ branded packaging due to production processes.

Brass plug available separately:

02021/1TP.

Specifications:

Please refer to the diagram in the product images.
Ø: 9mm.
l: 35mm.
l1: 10mm.
b: 1/4" UNC.
Weight: 0.02kg.

Useful Links:

Category: Explore our full range of zinc engine anodes.
Category: Explore our full range of Caterpillar engine anodes.
Blog: How often should a sacrificial anode be replaced on a boat?
Blog: Caterpillar anode and plug part number guide.