ERHC Energy Inc (ERHE)

[wzebra33]

The piston core "The piston core is our preferred coring device. It consists of a very heavy weight stand with a 60ft (18m), large-diameter core barrel assembly attached. A piston is placed on the inside of the coreliner and helps to recover cores with minimal disturbance. When filled with sediment, the entire device weighs nearly 6 tons."

http://nsm1.nsm.iup.edu/hovan/research/SPLAT/SPLAT-Pages/Image20.html
http://oceanworld.tamu.edu/students/forams/forams_piston_coring.htm