The Bi-polar two stage SPT has a lower section with two polished aluminium cylinder electrodes that clip together. This means the SPT can be used on its own and doesn’t require another electrode to complete the circuit.The overall length can be changed by substituting different length cylinders. A polished acrylic constriction is fitted between the upper and lower section. The head of the penis is drawn through the constriction with each pulsation of the Milker. Choose an internal diameter and length for the lower section, and an internal diameter for the constriction. Scroll down for detailed sizing information.

An adaptor kit is required (+£18) for use with the original Surge Milker.

Sizing:

This SPT has tighter lower section made up of two aluminium cylinder electrodes that clip together. A polished acrylic constriction is fitted between the upper and lower section. You need to specify three sizes...

Internal diameter (40mm or 50mm): The size refers to the internal diameter of the lower section. 40mm is by far the standard size.  Due to the way the milker works the sizes are not that critical - as long as the penis will fit inside the acrylic tube when erect. Diameter is calculated by dividing circumference by 3.142 (π)

Constriction: The constriction should be approximately 5mm smaller than the diameter of the erect head of the penis. 30 mm or 35mm constrictions fit into 40mm SPTs.  40mm or 45mm constriction for 50mm SPTs.

Length: The Length of the lower section is available in 95mm, 115mm, 125mm,140mm, or 155mm lengths – measured from mid way in the acrylic constriction to the base of the SPT. The length chosen should be the length closest to, but longer than, that of the erect penis, measured from abdomen to tip. This enables the head of the penis to be drawn through the constriction with each pulsation of the Milker.

If you require a different size or would like more information - just email us. You can do this before or after you purchase.

Additional lower lengths and constrictions are available to ensure correct sizing or for use with multiple players. An adaptor kit is also required (+£18) for use with the old Surge Milker.