Holdsworthy Aids 1963 seems to cover this topic. There are three types:-No1030 (English)with locking grub . I used one of these on an Apex alloy pump that was curved at the adaptor end. 1030/3 (French) to fit Zefal, no idea about this type. 1030/2 ( Italian) with square boss, I guess for Silca pump. All three types sold for ten shillings but I won mine for a prime in a thirds/junior race! ray Green, Brighton, England