Same Size, Different Shape
On many radial shockwave systems, the 15 mm size comes in two versions: a flat tip and a convex tip. They share the same diameter, fit the same handpiece and often appear in the same sessions. The difference is the geometry of the contact surface, and that changes which body areas each one suits.
The Core Difference: Contact Geometry
- Flat tip: a level, even contact plate. Pressure spreads uniformly across the surface, which gives a consistent feel on flat body areas.
- Convex tip: a domed metal face. The curved surface rocks naturally along rounded body contours instead of pressing only on the center.
Neither design is "better." They are tools for different shapes, and the physics behind the difference is contact area: at the same device output, the flat face spreads its impact over the full circle of the 15 mm plate, while the dome touches along a narrower curved band, so the same energy is delivered to less skin at any instant. The profile changes how pressure reaches the surface, not the wave the handpiece generates.
When the Flat Tip Makes Sense
Flat areas reward a flat contact: lower back, thigh fronts and backs, upper arms held against a flat surface, and any region where you want pressure spread evenly across a defined patch. The flat plate also makes it easy to keep the tip perpendicular to the skin, which many operators find steadier for longer sessions.
When the Convex Tip Makes Sense
Curved areas are where the dome earns its place: shoulders, deltoids, calves, around the knees and elbows: anywhere a flat plate would touch at the edges or rock on a single point. The convex face maintains line contact with rounded contours, so the pressure stays where you aim it.
Do You Need Both?
If your clients cover a mix of body areas, keeping both 15 mm versions is the usual setup. Switching between them mid-session takes seconds and removes the temptation to press harder with a poorly matched tip. If budget only allows one, start with the version that matches your most common working area and add the other later.
Building a complete tip set? The shockwave tip sizes guide maps every diameter from 6 mm to 25 mm to the body areas it suits.
Frequently Asked Questions
Are flat and convex tips interchangeable?
They fit the same handpiece socket and the same size range, but they perform differently depending on body shape. Swap them by area, not at random.
Does the dome shape change the depth of the wave?
No. On a radial system, penetration depth is determined by the device and technique, not by the tip profile. The convex face changes how the tip contacts the skin, not how deep the wave travels.
Which 15 mm tip should a new clinic start with?
Whichever matches your most frequent areas. Back-focused practices usually start flat; shoulder- and limb-heavy practices often reach for convex first. Many operators end up keeping both.
Do both tips use the same plastic cup?
On most systems, including the 3G pneumatic series, one cup size covers both flat and convex 15 mm tips. Always confirm the cup listing before ordering.
Both 15 mm versions (flat and convex) are available as replacements for the 3G pneumatic shockwave handpiece at Zetestech®, along with matching plastic cups.
Disclaimer: This article is for informational purposes only and does not constitute medical advice. It is not intended to diagnose, treat, cure, or prevent any condition. If you are pregnant, have a diagnosed medical condition, or take medication, consult a qualified healthcare professional before using the products or techniques described. Individual results vary.
Originally published by iTech Aesthetics — professional aesthetic and physiotherapy equipment for clinics and studios worldwide.