Welcome to the forum!
Are you referring to a disc brake spreader for rear disc brakes calipers with integrated parking brake, the kind that need to be rotated as they are compressed? If so, do you have access to the steel stock and machinist tools (metal stamp, mill, lathe)? If not, you might save money in the long run to order one.
Or, if it's just something you need for personal use when doing brakes, why not borrow the kit from your local chain auto parts store? As long as you return the tool within 90 days typically, it won't cost you anything.
-Rod