Watch out for your shock absorber covers to be made from CR graded neoprene. The CR grading (cellular neoprene rubber) has the best waterproof properties. You might know it from all high-end surfing kits too. 
Shocktube products enclose your rear shock absorber and spring. They help preventing damage from road salt, water spray, stone chipping, dust or dirt. Fitting most monoshock or twin shock systems, those shock absorber covers are made from top quality CR Neoprene. 
