The new Ventus design 15/18 - they have just introduced it with 18m tips first. The JS3 is also a 15/18m design (I have the pricelists and 3-view specs for both spans) and the 18m version will use the same tips as the 21m JS1c - just as the 15m version uses the tips designed for it but that were first used as the 18m JS1 EVO tips.