This stove is badged as Primus so I've included the post here and not in the Sievert gallery, but it's pretty much the end of the line of the 'yellow and orange' series of butane stoves that Dave Gibson rightly referred to as 'klunky' in this post Video killed the radio star With the yellow and orange klunky gassies that preceded it fuelled by screw-fitting cartridges, this is perhaps something of a retrograde design, taking pierceable cartridges that were Primus/Sievert copies of contemporary Campingaz carts If you can't beat them join them as the saying goes, and it looks like Primus-Sievert AB decided to shelve their technically superior screw fitting gas cartridges to snatch some of the Campingaz pierceable cartridge stove market share. Unsurprisingly, Campingaz cartridges fit the stove The piercing of the cartridge happens when the base component is screwed home, a lock button snicking into place when it does so The control valve isn't easily user serviceable, having a control spindle held captive by a retaining pin that's burred over at each end, so it would have to be drilled out to replace a leaky O-ring seal I feel it was a low point for Primus-Sievert, with a long and noble history of much better quality products and some decent ones to their name in later years. It didn't deter them however from proudly placing a sticker on the box announcing the company's centenary (for Sievert, not Primus, which had theirs ten years later) John