There’s no other word but a single Chinese character 筆 (bi) meaning for ‘pen’. This is a traditional Chinese writing still been officially used in Hong Kong and Taiwan, while mainland China has simplified it to 笔 (bi) instead. There’s no other description, but I believe the shop owner was telling people the pen is now available selling in the shop. A bit unusual, though. I was wondering why I was attracted by the writing and have finally figured out because it looks like 舞 (wu), another Chinese character for 'dancing’. You can copy 舞 and paste it on google image search page, you’ll know what I mean.