The black knight ion element psx selby double pack contains two squash rackets full of technology customised for daryl selby the rackets are head light with a head size of 475cm2 736in2 and are strong and powerful yet controlled stable and aerodynamically efficient thanks to power surge nano crystalline and thin k technology vibrations have been reduced and the durability has been increased with the rackets strung with powernick 19 strings for extra power and performance full length pr