This product factory direct sales, has various specifications, 30 long, 35 long, 40 long, 50 long, under the order message note, did not indicate the default 50 long. There are special specifications please contact the owner, can be customized. You can also leave a note. This shop can sell any specifications of diamond grinding wheel cutter, diamond diamond pen, welcome to order, we use natural diamond system, reasonable structure, beautiful shape, inlaid solid, durable. Where to buy the store knife grinding wheel, there are quality problems in the use of that, three packs of products (guaranteed repair, replacement, return).