From the description on the site's Tygon tubing page
, 2375 sounds more chem resistant than 2475. However, according to the info, 2475 is noted for not being prone to releasing its own constituents or allowing outside lements to permeate it...and those are key for keeping brake fluid pure which is the whole reason for using Tygon tubing over other kinds of tubing. 2475 also looks like it is clearer from the pics on the above linked page.
Tygon® 2375 Ultra Chemical Resistant Tubing
This tubing offers an unequaled combination of chemical resistance, clarity and flexibility. It is virtually unaffected by acids, bases, ketones, salts and alcohols, enabling it to meet the requirements of many applications, from filling battery acid to handling hazardous material.
Non-DEHP & plasticizer-free
Will not prematurely embrittle or crack
Exceptionally smooth, inner bore
Reduces the potential for contamination
Non-DEHP & plasticizer-freeInhibits particulate buildup
Durometer hardness (shore A): 75
Temperature range: -103°F to 130°F
Meets FDA standards, EU & NSF 51 compliant
Tygon® 2475 High-Purity Tubing
Ideal for handling sensitive fluids such as pharmaceutical or biological solutions. There is virtually no absorption of key fluid constituents into the tubing material or fluid absorption onto the tubing walls.
Plasticizer free
Virtually no extractables
Extremely low sorption to aqueous fluids
Unaffected by sanitizers & cleaners
Durometer hardness (shore A): 72
Temperature range: -94°F to 125°F
Biocompatibility to the ISO 10993 standard
Meets FDA & USP Class VI standards
08 MIDNIGHT SAPPHIRE BLUE ZX-14 Now Deceased, will be resurected
2024 ZX-14R bran friggin NEW!