Close to Kungsportsplatsen is Friluftsbolaget (the Outdoors Company) and they sell almost anything that has to do with hiking or outdoor activities. The prices can be a bit steep, but the equipment is all in high-quality brands. And if you are looking for a classic Swedish rucksack, Fjällräven Kånken, this is where you should go. Friluftsbolaget also has a good website with an online store. To get here, take trams 3, 4, 5, 6 or 8 to Kungsportsplatsen.