These blades are designed to fit my marking knives.
This particular style, the SM04, is not what I recommend using for woodworking. However myself and a few other users have commented on how useful this is as a ‘desk knife' for opening packaging for example. Plus it looks kinda cool!
Please note that it is much more cost effective to purchase these directly from Swann Morton! The reason I'm listing them here is by request, mainly to make them more convenient for customers to purchase and have the ability to combine delivery costs.