Dont Let Low Power Supply Hold You Back With This Helpful Phone Accessory. The Power Supply Is Designed To Work With Your Existing Yealink Phone, So You Can Keep It Working Effectively. Yealink Power Supply For Use With The Sip-T21(P) Sip-T19(P) Sip-T23(P) W52P W52H Sip-T23g Sip-T40P.