this chisel is selling on ebay for less than £8 with postage!
The chisels that are on Ebay are not Armeg chisels, they are similar which is stated in some of the adverts.
Anorak on now, please bear with me !
I am unsure of the quality of these chisels as I have not tested them.
If an SDS chisel fails it usually fails across the shank where the SDS grooves are machined.
Up until a few years ago you had to have a license from Bosch(who invented the SDS drive system) to produce SDS shanked accessories. This involved being visited by Bosch and having your products tested by them to make sure they satisfied their specification regarding materials, heat treatment, tolerances etc. If they didn't like what they saw you didn't get the license.
That license has now expired and so anyone can make SDS accessories which is now happening with varying degrees of quality.
The 2 major problems are:-
1) incorrect heat treatment - this means the chisel can snap across the SDS shank which usually means you have a piece of shank inside your power tool chuck which can only be removed by a power tool repairer (it may mean a new chuck).
2) incorrectly machined grooves on the shank. There are two different types of groove on the shank. There are two drive grooves(the squarer ones) and two "ball nosed grooves". The ball nosed grooves accept spring loaded balls to stop the accessory from falling out of the chuck. If the drive grooves are machined too wide, the accessory turns slightly in the chuck and it tries to drive on the spring loaded balls. This can cause damage to the chuck and can also make accessory removal difficult.
I am not suggesting that the Ebay products are poor quality, as I said I have not tested them, they may be very good.
I just wanted to make people aware of the problems associated with cheaper SDS accessories.
Also, when you use SDS shanked accessories, grease the shank at regular intervals, try to minimise leverage and allow the accessory to cool at room temperature if the shank becomes hot. These measures should prolong the life of your accessory and, more importantly, your power tool.