Fewer holes drilled in poles. Facilitate subsequent inspection for shell thickness and hole depth. Can be either hammered or screwed into place. Easier to install than non-tapered plugs, particularly in below ground line locations. Unauthorized removal is discouraged because of the requirement to use a removal tool.
Standard colour is black.
Other colours are available if colour coding is desired. Recipient of honourable mention in the 1993 Canadian Industrial Awards competition. An approved product for sealing treatment and inspection holes in wood - American Wood Preservers Association Book of Standards.