The name is due to the stitch pattern on the front side, which recalls the structure of bamboo plant.

S (eu35-36/US4.5-5/UK3-3.5)
M (eu37-38/US5.5-6.5/UK4-5.5)
L (eu39-40/US7-8/UK5.5-6.5)
XL (eu41-42/US8-9.5/UK7-8.5)

Instructions are intended for working in magic loop, or dpns.