Quick comparison of BHB7 17 and Black Widow 17 since a couple of people have enquired.
Yes, they're both back and 7 sided. No, they're not the same string. In fact, they feel and perform very differently.
Black Widow is unbelievably soft, very comfortable, more muted and more dampened feeling than BHB7. It fact, Black Widow barely feels like a poly. Touch play is very good because of its softness and the fact that it doesn't have the springiness of BHB7. You can feel the ball so much more with volleys. However, if you like crisp feeling strings, you probably won't like Black Widow. Also it doesn't have the spin of BHB7 and doesn't allow you to hit quite as heavy a ball. Also there's no way Black Widow 17 is 1.26mm - its much closer to 1.20mm. It would be worth trying the '16' gauge if you normally choose 17 gauge strings from other manufacturers.
BHB7 is more the performance orientated string and there are many comments about it already in this thread.
Comparison of Weiscannon B5E 17 and BHB7 17 from another thread: