GE 2-Pack White Lamp holder in the Fluorescent Lighting Parts & Accessories department at Lowes.com
Non-shunted Turn Type T8 Lamp Holder JACKYLED 20-Pack UL Socket Tombstone for LED Fluorescent Tube Replacements Medium Bi-pin Socket for Programmed Start Ballasts - Amazon.com
Kulka 1550 Non Shunted Socket for Medium Bipin (G13) Fluorescent Lamps - My Lighting Solutions
Leviton Low Profile Shunted Medium Bipin Fluorescent Socket | Medium Bi-pin Socket (Shunted) | Bulbs.com
G13 Nonshunted Lamp Holder for 4' Bi-Pin Tube Lights