Polyethylene [PE] tubing for pneumatic instrument control applications requiring plenum-rated tubing. Plexco 2600 series pneumatic tubing is intended for indoor use and for low pressure pulse control circuit applications of ? 1 atm [14.69 psi]. Plexco 2600 series pneumatic tubing is manufactured from a polyethylene [PE] material. Solid black tubing marked with a white ink numbering system over its full length. Cut the lead end at any given number [from 1 to 30] for easy identification of individual pneumatic circuit tubes.