The tip on Under Needle is a very small sharp cone set directly into the gear housing, which is what makes it the shortest bit family in the game — “Under” sits two millimetres below standard height, twice the drop of a “Low” part. Needle and High Needle share the sharp-point concept; Under Needle is the version that trades every bit of height away for it. It barely travels, holding station near the centre.
That low profile is the real selling point. Tucking the ratchet down out of reach makes a combo markedly harder to burst, and the low-friction point gives strong raw spin retention — better, by some accounts, than Ball.
The problem is that Beyblade X carries its weight high. Sharp tips under top-heavy builds tilt, wobble and topple well before they run out of spin, which is why defence combos underperform their stamina figures. Current reads call Under Needle too risky for tournament use, while flagging it as the obvious partner for very tall stamina blades whose main weakness is bursting. Breakage is documented here too, at the notched ring around the bit.