Titan Tools 16150 Locking Universal Joint Adapter Set - 5 Piece Includes increasing drive adapters (1/4" to 3/8"), (3/8" to 1/2") and (1/2" to 3/4") Includes reducing drive adapters (1/2" to 3/8") and (3/8" to 1/4") Chrome-moly impact grade construction with easy to read laser etched sizes Pin-free hex locking design is 3X stronger than traditional pin type designs Can be used as a swivel when pulled out, or locked in place when pushed in