One or more air deflection assemblies are used to redirect air emitted by computers in a rack-based computer system. The single-piece spring has a pair of outer spring sections extending from the arms and a center portion with a cam follower which bears against a cam surface on the cartridge to bias the cartridge as it moves relative to the handle head. X=a group having the following formula at the terminal thereof, W=a group having HO\u2014CH2CF2O\u2014 at the terminal thereof, Z=a group having CF3a3O\u2014 at the terminal thereof, Y=a valent perfluorinated hydrocarbon group or the like, s=1 to 7, t=0 to 4, u=0 to 2, =2 to 7, a3=0 to 19, and R1 to R5=a hydrogen atom, a fluorine atom, etc.