There are a number of different designs of Compact Fluorescent Lamp CFL on the market which can make it quite confusing to decide which is design is the best one to go for.

The semi spiral light bulb has always been fairly common in the US market and has recently been introduced to the UK. Again the 23W Half Spiral Energy Saving Bulb CFL is simply a long thin fluorescent tube which is looped around in a spiral shape but the first portion of the fluorescent tube just goes up vertically. Accordingly the semi spiral name is derived because this 4U Lotus 85w 105w CFL bulb is half linear and half spiral and therfore designated as a semi spiral. The overall look of the bulb is more akin to the traditional bulb and because of the fact that the fluorescent tube swings outwards it has a larger diameter than the linear CFL and accordingly the overall height can be reduced and the bulb will still produce a similar level of lumens output.
23W Half Spiral Energy Saving Bulb CFL