These lightweight 1/4 turn self eject fasteners are made from aluminium and are 50% lighter than the Dzus steel equivalent. Swapping to these is an easy way to save weight on race car or bike. Sizing is the same as Dzus fasteners so changing is like for like.Suitable for fastening flat or curved panels with a simple push and turn. When released a spring self ejects the pin which also acts as a quick indicator if a fastener has not been fastened properly. The pin locates on a spring (available separately) which is riveted to the back panel and can be deflected to get a secure fixing.Available in 2 body sizes:37mm baseplate with 27mm between rivet holes.44mm baseplate with 32mm between rivet holes.To work out which length of fastener you require add the total material thickness to the spring clearance. Subtract the spring deflection (0.047" for the S5 spring / 0.062 for the S6 spring). This dimension is your material depth, or 'grip' thickness.Attachment springs (available separately): F