A lot of tiles these days need to be cut with a wet cutter... they wont cut with a normal wheel cutter.. tiles such as slate, marble, quartz ,some porcelain... when buying a wet cutter go for the best you can afford, if tiling on a regular basis , i would recommend Rubi... I have 3 wet cutters and have owned them over 20 years with no problems... and thats with very regular use, if your doing the occasional job, you can buy cheaper table cutters for around 50 pounds or so... these will do for the odd kitchen shower etc...