[StunZeeD]

What are the differences between these 2 guides?

 

[PhilipW]

The LG1+ is our flagship aluminum World Cup race chainguide. It is designed from the ground up to work for this purpose, and at 170 grams it is the lightest/strongest guide on the market for this level of racing.
http://www.e13components.com/product_lg1plus.html

The LS1+ is our newer lower priced ($90 MSRP) alternative to those who do not require or want all the weight savings offered by the LG1+. It offers similar performance to the LG1+, just at a lower cost. The backplate is also non adjustable, however the backplate has a chainring range from 32T-40T. Weight is 250g.
http://www.e13components.com/product_ls1plus.html

Both guides can take a pretty good beating.