McMaster 5187K65 50 ft Soft PVC Tubing for Fuel and Lubricants 3/8" ID, 1/2" OD 17311-11D which is a more accurate

which is a more accurate term since solid state electronic relays

per stroke

Female Input Square Drive 1/2 in

With a high-quality steel construction and an 8 oz head weight

McMaster 5187K65 50 ft Soft PVC Tubing for Fuel and Lubricants 3/8" ID, 1/2" OD 17311-11D which is a more accurateMcMaster 5187K65 50 ft Soft PVC Tubing for Fuel and Lubricants 3 8" ID, 1 2" OD The industry standard for fuel and lubricant applications, this tubing can be used intermittently with petroleum based products without becoming hard or brittle. Do not use with ethanol based gasoline. It is flexible, so it bends easily around objects. PVC tubing is the most economical option. Clear tubing allows you to easily monitor flow.